Surveying

Explanation: The principle of working from whole to the part in surveying ensures that any errors made during the surveying process are minimized. By establishing a framework of larger components before moving on to more detailed aspects, the risk of compounding errors is reduced.

Explanation: Working from whole to part in surveying aids in preventing the accumulation of errors and localizing any potential errors that may arise during the survey. This method ensures a systematic approach to the surveying process and enhances the accuracy of the final results.

Explanation: When the extent of a survey exceeds 260 square kilometers, the curvature of the Earth’s surface becomes significant, and it must be considered to ensure accurate measurements and calculations during the surveying process.

Explanation: Geodetic surveying differs from plane surveying in that it takes into account the curvature of the Earth. This is essential when dealing with large areas, as the surface of the Earth is not flat and can affect the accuracy of measurements and calculations.

Explanation: Hydrographic surveying primarily focuses on the mapping and measurement of large water bodies such as seas, oceans, and lakes. It involves the study of underwater features, tides, currents, and the topography of the ocean floor.

Explanation: An astronomical survey involves determining the absolute locations and directions of any line on the Earth’s surface by observing celestial bodies. This method is crucial for establishing precise locations, especially in remote areas where other surveying techniques may be challenging to implement.

Explanation: A diagonal scale represents either three units or only one unit and its fractions up to the second place of the decimal point. It is commonly used in various fields, including engineering and cartography, for accurately measuring distances and quantities on maps or technical drawings.

Explanation: A retrograde vernier is characterized by having its smallest division longer than the smallest division of the primary scale. This type of vernier scale is used in various precision instruments for accurate measurement and reading of values.

Explanation: The scale of chords is specifically used to measure and set out angles. It is commonly employed in trigonometry and navigation for various applications, including mapmaking, land surveying, and architectural design.

Explanation: The least count, in this case, is given by the ratio of the value of one smallest division on the main scale (S) to the number of divisions on the vernier (n). Understanding the least count is crucial for accurately reading and interpreting measurements on precision instruments.

Explanation: In surveying, a discrepancy refers to the difference between two measured values of the same quantity. Recognizing and resolving discrepancies is essential for ensuring the accuracy and reliability of survey data and measurements.

Explanation: The Representative Fraction (R.F.) of 1cm = 5m is 1/500. This ratio signifies the relationship between the measurements on the map and the corresponding measurements in the real world, helping to accurately represent large-scale features on a smaller map.

Explanation: The scale designation recommended by IS: 1491-1959 spans from A to F. This standard scale designation is commonly used in various surveying and mapping practices, ensuring uniformity and consistency in scale representation.

Explanation: The least count is not directly associated with either the smallest division of the primary scale or the secondary scale. Instead, it is a concept used to denote the smallest measurement that can be read or estimated from a measuring instrument, emphasizing the instrument’s precision.

Explanation: The scale 1cm = 10,000m represents the smallest scale among the provided options. This scale indicates that one centimeter on the map corresponds to ten thousand meters in the actual physical world, indicating a large-scale representation suitable for detailed mapping and surveying.

Explanation: Compensating errors in chaining or other surveys exhibit a relationship with the square root of the length of the line. Understanding this relationship is essential for effectively managing and compensating for errors to ensure the accuracy and reliability of survey measurements.

Explanation: Negative errors occur in the chain when its length exceeds the standard length. Recognizing and addressing negative errors is crucial for maintaining the accuracy and precision of measurements during the surveying process.

Explanation: The theory of probability is commonly applied to accidental errors in surveying. By understanding the probability distribution of errors, surveyors can effectively manage and minimize the impact of accidental errors on the overall accuracy of measurements.

Explanation: The principle of least square states that the most probable value of an observed quantity is the one that minimizes the sum of the square of errors. This principle is fundamental in statistical analysis and plays a crucial role in minimizing the impact of errors in surveying.

Explanation: The residual error represents the difference between the most probable value of a quantity and its observed value. Understanding and managing residual errors are crucial for ensuring the accuracy and reliability of survey measurements and data analysis.

Explanation: The permissible error represents the maximum allowable limit up to which a measurement may deviate from the true value. Understanding the permissible error is crucial for ensuring that survey measurements fall within an acceptable range of accuracy and reliability.

Explanation: Systematic errors, unlike random errors, are of a cumulative nature and can be corrected through careful calibration and adjustment of measuring instruments. Identifying and addressing systematic errors are crucial for ensuring the accuracy and reliability of survey measurements.

Explanation: Accidental errors in surveying are typically proportional to the square root of the number of observations taken (n). Understanding this relationship is essential for effectively managing and minimizing the impact of accidental errors on the overall accuracy of survey measurements.

Explanation: Among the options provided, a chain survey is considered the simplest type of survey. It involves the basic process of measuring distances and angles using a chain and other simple tools, making it a fundamental technique in the field of surveying.

Explanation: Chain surveying is commonly used for surveying small areas that are relatively flat and even. This method is well-suited for obtaining accurate measurements and creating detailed maps of areas with minimal variations in terrain elevation.

Explanation: A Cadastral Map is a large-scale map that delineates the boundaries of land parcels, providing detailed information about land ownership, property lines, and other relevant cadastral data. These maps are crucial for land management and real estate purposes.

Explanation: Cadastral surveys are specifically used to accurately determine and fix property lines, boundaries, and land ownership. These surveys are crucial for legal and administrative purposes, ensuring clarity and transparency in property ownership and land management.

Explanation: An offset scale can have the zero mark positioned either at the middle or at the end, depending on the specific design and application requirements. This flexibility allows for precise and accurate measurements in various surveying and engineering tasks.

Explanation: Offsets in surveying refer to small measurements taken perpendicular to the chain line. These measurements are essential for accurately mapping and positioning features that are not directly accessible from the main surveying line, contributing to the overall precision of the survey data.

Explanation: Short offsets in surveying are commonly measured using an ordinary chain. This method allows for accurate measurements of small perpendicular distances from the main surveying line, contributing to the overall precision and detail of the survey data.

Explanation: Butt rods are primarily used for measuring offset distances in surveying. They aid in accurately determining perpendicular distances from the main survey line, contributing to the precision and detail of the survey data.

Explanation: When a 30m chain is found to be 20cm too long after chaining 1500m, the correct length of the total distance chained would be 1505m. Adjusting for the discrepancy ensures the accuracy of the final measurement.

Explanation: Among the options provided, the chain length that is not the standard metric chain length is 25m. Understanding standard measurement units is crucial for ensuring accuracy and consistency in surveying and other related activities.

Explanation: When a chain is found to be too short on testing, it can be adjusted by various methods, including straightening the links, inserting additional circular rings, or flattening the circular rings. Ensuring the accuracy and reliability of the chain is essential for precise survey measurements.

Explanation: A 30m metric chain typically consists of 150 links. Understanding the composition and structure of the measuring instruments is crucial for accurate and reliable survey measurements.

Explanation: A chain 33 feet long, consisting of 16 links, each 2(1/16) feet long, is known as a Revenue chain. Different types of chains have specific applications in various fields, contributing to the accuracy and precision of survey measurements.

Explanation: A chain is typically made up of mild steel or galvanized iron wire with a diameter of 5 mm. Understanding the materials and specifications of surveying equipment is essential for ensuring accurate and reliable measurements.

Explanation: Ranging in surveying involves marking some intermediate points in a straight line and then joining the two endpoints in the field. This process is essential for establishing reference points and ensuring the accuracy of the survey measurements.

Explanation: Main stations in surveying are the important points selected at the ends of the chain lines to command the boundaries of the survey. These stations serve as essential reference points for accurately delineating and mapping the survey area.

Explanation: The longest chain line passing through the center of the area is referred to as the base line. This line serves as a fundamental reference for various surveying activities and is essential for establishing accurate measurements and spatial relationships within the surveyed area.

Explanation: The tie line is used in a survey to take details of nearby objects, helping to accurately map and position these objects in relation to the surveyed area. This process contributes to the overall precision and detail of the survey data.

Explanation: When measuring on rough or hilly ground, the permissible limits of error in chaining are often denoted as 1:250. Understanding these limits is crucial for ensuring accurate and reliable measurements in challenging terrain conditions.

Explanation: In the scenario described, the distance of the follower from the starting point would be five chains. Understanding the signaling system is crucial for maintaining effective communication and ensuring the accuracy of measurements during the surveying process.

Explanation: Invar tapes are made of an alloy of nickel and steel, known for their low thermal expansion. These tapes are commonly used in surveying and metrology applications, ensuring accurate and reliable measurements under varying temperature conditions.

Explanation: Metallic tapes in surveying are typically made of cloth and wires, providing flexibility and durability for various measuring applications. Understanding the characteristics of surveying tapes is essential for ensuring accurate and reliable measurements in the field.

Explanation: Chain surveying is commonly used for surveying small areas in open ground, making it a practical and effective method for obtaining accurate measurements and creating detailed maps of relatively straightforward terrains.

Explanation: The steel band is preferred over the chain for accurate work due to its practical inextensibility. This characteristic ensures minimal stretching or elongation during measurements, contributing to the overall precision and reliability of the survey data.

Explanation: An Engineer’s chain typically has a length of 100 ft. Understanding the standard measurements of surveying equipment is essential for ensuring accurate and reliable measurements in various surveying applications.

Explanation: Measuring horizontal distance using the stepping method is more challenging when moving uphill. Understanding the impact of terrain on surveying methods is crucial for ensuring accurate and reliable measurements in various field conditions.

Explanation: When measuring horizontal distance using the stepping method, it is recommended to follow downhill paths. This approach helps maintain consistency and accuracy in the measurements, ensuring reliable survey data collection in varying terrain conditions.

Explanation: The sag correction for a chain, given the weight (W), span (L), and tension (P), is determined by the formula LW^2/24P^2. Understanding the sag correction is crucial for ensuring accurate and reliable measurements in surveying applications, especially over longer spans.

Explanation: Normal tension refers to the pull that neutralizes the effects caused by both pull and sag in surveying measurements. Understanding the concept of normal tension is essential for ensuring accurate and reliable measurements, especially when accounting for gravitational effects on surveying instruments.

Explanation: The slope correction, given the angle of the slope (Θ), the length of the slope (L), and the difference in elevation (H), is determined by the formula 2Lsin^2 Θ/2. Understanding the slope correction is crucial for accurate and precise measurements in surveying, particularly in areas with varying terrain elevations.

Explanation: The correction for temperature per tape length, given the standardized temperature and the recorded temperature, is calculated to be + 0.01674m. Understanding the impact of temperature variations is essential for ensuring accurate and reliable measurements in surveying applications.

Explanation: Chainage refers to the distance measured along a chain line during surveying. Understanding the concept of chainage is crucial for accurately mapping and positioning features and points of interest along the surveyed area.

Explanation: The length of offset in surveying depends on various factors, including the desired accuracy, scale of plotting, and nature of the ground. Understanding these factors is essential for ensuring the precision and detail of the survey data and measurements.

Explanation: Given the maximum angular error in laying the direction and the corresponding displacement on paper, the accuracy in the offset measurement is determined to be 1 in 19. Understanding the relationship between angular errors and offset measurements is essential for ensuring accurate and reliable survey data collection.

Explanation: A French cross-staff is capable of setting angles of either 45° or 90°. Understanding the capabilities and applications of surveying instruments is crucial for ensuring accurate and precise measurements in the field.

Explanation: The perpendicular offset method in surveying involves minimal ground measurement and is effective for accurately positioning features perpendicular to the main survey line. Understanding the various offset methods is crucial for ensuring efficient and accurate survey data collection.

Explanation: The sag correction in surveying is always negative, accounting for the downward displacement of a chain due to gravitational effects. Understanding the nature of sag correction is essential for ensuring accurate and reliable measurements in various surveying applications.

Explanation: The open cross-staff is specifically suitable for setting out long offsets during surveying operations. Its design enables accurate measurement and alignment of features that are further away from the main survey line.

Explanation: In an optical square, the angle of intersection between the horizon mirror and the index mirror is set at 45 degrees. This angle is crucial for accurate angular measurements in surveying and related applications.

Explanation: Unlike an optical square, a prism square does not require any adjustments because the angle between the reflecting surfaces remains fixed. This design characteristic allows for convenient and efficient measurements in various surveying tasks.

Explanation: The initial step in chain survey execution is reconnaissance, which involves preliminary examination and assessment of the survey area to gather essential information before commencing the surveying process.

Explanation: In surveying, a river serves as an obstacle primarily to the process of chaining, but it does not significantly impede the ranging process. Understanding the challenges posed by different types of obstacles is essential for effective and accurate surveying.

Explanation: A hill typically impedes the ranging process in surveying due to its elevated and uneven terrain, but it does not necessarily hinder the chaining process. Understanding the impact of different types of obstacles on surveying operations is crucial for successful and accurate data collection.

Explanation: Buildings can present obstacles to both chaining and ranging processes in surveying, depending on their proximity and layout in the survey area. Understanding how buildings affect surveying operations is essential for ensuring accurate and comprehensive data collection.

Explanation: When a field is measured using a chain that is 1.0 percent too long and is initially found to be 10,000 acres, the corrected area of the field is calculated to be 10201 acres. Understanding the impact of measurement errors on surveying results is critical for ensuring accurate and reliable data analysis.

Explanation: A 30 m long chain, when tested, should demonstrate errors within the range of ±2mm per meter and ±8mm overall length. Understanding the permissible error limits is crucial for ensuring the accuracy and reliability of surveying measurements and data analysis.

Explanation: Offset angles taken in a chain survey can vary and may be set at 45°, 90°, or 135°, depending on the specific requirements of the surveying project. Understanding how to determine and set offset angles accurately is essential for ensuring precise and reliable data collection.

Explanation: An offset that exceeds 15 meters in length is referred to as a long offset in the context of chain surveying. Understanding the classification of different types of offsets is crucial for effective survey planning and execution.

Explanation: Each statement represents a correct concept in the context of surveying and error analysis. Understanding these concepts is essential for ensuring accurate and reliable data interpretation and analysis in surveying applications.

Explanation: A well-conditioned triangle typically has an angle between 30° and 120° in the context of surveying and geometric calculations. Understanding the characteristics of well-conditioned triangles is crucial for accurate and reliable data analysis and interpretation.

Explanation: Triangulation in a chain survey serves the purpose of establishing accurate control points for precise and reliable measurements. Understanding the significance of triangulation is essential for ensuring the accuracy and integrity of surveying data and measurements.

Explanation: Handles in chain links are typically connected by swivel joints, allowing for flexible movement and maneuverability during the surveying process. Understanding the design and functionality of chain handles is essential for ensuring efficient and accurate data collection in various surveying applications.

Explanation: Handles of chains are commonly made of brass due to its durability and corrosion resistance, making it suitable for use in various surveying conditions. Understanding the materials used in chain construction is essential for ensuring the longevity and reliability of surveying equipment.

Explanation: A French cross-staff is capable of setting out an angle of 45° with the chain line during surveying operations. Understanding the capabilities and limitations of different surveying instruments is essential for ensuring precise and accurate measurements in the field.

Explanation: The optical square operates based on the principle of double reflection, enabling accurate angle measurements in surveying and related applications. Understanding the underlying principles of surveying instruments is essential for ensuring their effective and accurate use in the field.

Explanation: Perpendicular offsets provide a more accurate means of fixing the position of a point during surveying operations, enabling precise measurements and alignments in relation to the main survey line.

Explanation: Positive errors can occur in various situations, such as when the length of the chain is shorter than the standard, slope and sag corrections are not appropriately applied, or measurements are made along incorrectly aligned lines. Understanding the factors contributing to positive errors is crucial for ensuring accurate and reliable surveying data.

Explanation: Invar tapes are commonly used for baseline measurements due to their high precision and minimal thermal expansion properties. Understanding the appropriate instruments for specific surveying tasks is crucial for ensuring accurate and reliable measurements.

Explanation: The accuracy of measurement in chain surveying is influenced by various factors such as the length of the offset, the scale of the plotting, and the importance of the features being surveyed. Understanding the factors that impact measurement accuracy is essential for ensuring precise and reliable surveying data.

Explanation: The accuracy of measurements in chain surveying is not directly influenced by the role of the leader within the surveying team. However, the skills and expertise of both the leader and the follower contribute to the overall accuracy and reliability of surveying data.

Explanation: The indirect ranging method is employed when two points of the chain line are mutually invisible, requiring alternative surveying techniques to establish accurate measurements and alignments. Understanding the various ranging methods is essential for ensuring effective surveying operations in challenging conditions.

Explanation: The scale of 1:25000 on a map indicates that one centimeter on the map represents 25000 centimeters in the actual field. Understanding map scales is essential for accurately interpreting and analyzing geographic information represented on maps.

Explanation: Tacheometric surveying is a suitable method for conducting surveys in mountainous regions due to its ability to facilitate measurements and calculations over large distances and uneven terrains. Understanding the appropriate surveying methods for specific geographical locations is crucial for ensuring accurate and reliable data collection.

Explanation: When a chain line encounters a river, the chaining process may be obstructed, but ranging can often be performed without significant obstacles. Understanding how different geographical features impact surveying operations is essential for ensuring effective and accurate data collection.

Explanation: Prolongation of a chain line across an obstruction is often achieved by drawing perpendiculars with a chain, enabling accurate measurements and alignments in the presence of obstacles. Understanding the various techniques for overcoming surveying obstacles is essential for ensuring effective and accurate data collection in the field.

Explanation: The limiting length of an offset is determined based on various factors, including the accuracy of the work, the method of setting out perpendiculars, and the scale of plotting. Understanding the factors that influence the appropriate length of offsets is essential for ensuring accurate and reliable surveying data.

Explanation: Errors due to bad ranging can lead to cumulative positive discrepancies in surveying measurements, impacting the overall accuracy and reliability of the collected data. Understanding the sources and implications of ranging errors is essential for ensuring precise and dependable surveying results.

Explanation: The construction of a highway railway typically requires the creation of both longitudinal and cross sections to ensure accurate planning and implementation of the railway project, taking into account the specific geographical features and requirements of the construction site.

Explanation: In compass surveying, the direction is primarily measured by the compass, while the length of the survey line is typically measured using a chain or tape. Understanding the fundamental principles of compass surveying is essential for accurate and reliable surveying operations.

Explanation: In a prismatic compass, the magnetic needle and graduated circle remain stationary, enabling accurate directional measurements while allowing the user to maintain a stable line of sight during surveying operations.

Explanation: In a closed traverse, the sum of included angles should be (2N-4) right angles, where N represents the number of sides. Understanding the principles and requirements of a closed traverse is essential for ensuring accurate and reliable surveying data.

Explanation: Traversing methods such as chain traversing, loose needle method, chain angle method, and fast needle method are commonly adopted for conducting various types of surveying operations, enabling precise measurements and alignments during traversing processes.

Explanation: The graduations in a prismatic compass are typically inverted and run clockwise, with 0° positioned at the south point. Understanding the specific features and functionalities of a prismatic compass is essential for ensuring accurate directional measurements during surveying operations.

Explanation: True meridians refer to imaginary lines that converge at a point called the pole, aiding in the accurate determination of geographical directions and positional alignments during surveying operations.

Explanation: In the whole circle system, bearings are typically measured clockwise from the north point of the reference meridian, aiding in accurate directional measurements and alignments during surveying operations.

Explanation: The quadrantal system allows the user to measure bearings from either the north point or the south point, depending on which point is closer, enabling efficient and accurate directional measurements during surveying operations.

Explanation: A bearing noted as N45° E is an example of a direction measured in the quadrantal system, providing precise directional information for accurate surveying measurements and alignments.

Explanation: Converting the whole circle bearing 338°42″ into the quadrantal form results in the notation N 21°18′ W, representing the specific direction and alignment for accurate surveying measurements and calculations.

Explanation: The conversion of the quadrantal bearing N 35° W into the whole circle bearing results in the direction 325°, providing accurate directional information for precise surveying operations and calculations.

Explanation: The prismatic compass and the surveyor’s compass are specifically designed to provide accurate directional measurements, including the whole circle bearing and the quadrantal bearing of a line during surveying operations.

Explanation: In normal conditions, the difference of the fore and back bearings should ideally be 180°, aiding in accurate directional measurements and alignments during surveying operations.

Explanation: The calculation of the included angle BAC based on the whole circle bearings of lines AB and AC results in an included angle of 74°, providing accurate directional information for precise surveying measurements and calculations.

Explanation: Local attraction at a place in compass surveying can be attributed to various factors, one of which includes the presence of current-carrying base wires that can influence the accuracy of directional measurements and alignments during surveying operations.

Explanation: The correction due to local attraction at a place is typically consistent and constant for all bearings, aiding in the accurate adjustment of directional measurements and alignments during surveying operations.

Explanation: An instrumental error in compass surveying can arise due to the absence of a counterweight provision to counteract the dip, leading to inaccuracies in directional measurements and alignments during surveying operations.

Explanation: By considering the bearings of AB and BC, the angle < ABC can be calculated to be 110°, aiding in the accurate determination of the angle for precise surveying calculations and measurements.

Explanation: The smaller angle that a survey line makes with the true meridian is referred to as the azimuth, providing essential directional information for accurate surveying measurements and calculations.

Explanation: The azimuth and altitude of a star can vary due to diurnal motion, necessitating careful considerations and adjustments during surveying operations to ensure accurate and reliable measurements and alignments.

Explanation: The whole circle bearing (W.C.B) of a line is preferred over a quadrantal bearing because the former fully specifies the bearing using an angle, ensuring precise directional measurements and alignments during surveying operations.

Explanation: In the case of a line AB, the forebearing and back bearing of the line typically differ by 180°, enabling accurate directional measurements and alignments during surveying operations.

Explanation: Local attraction in compass surveying can be attributed to various factors, including the presence of magnetic materials that can interfere with the accuracy of directional measurements and alignments during surveying operations.

Explanation: The inclination of the needle to the horizontal towards the pole is known as the dip, an essential concept in compass surveying that influences the accuracy and reliability of directional measurements and alignments.

Explanation: The dip of the needle can vary from one location to another, with its value being zero at the equator and reaching its maximum at the poles, affecting the accuracy and precision of directional measurements and alignments during surveying operations.

Explanation: The quadrantal bearings (Q.B) of the lines corresponding to the given whole circle bearings (W.C.B) are N, S45°E, and W90°, highlighting the specific directional information required for accurate surveying measurements and calculations.

Explanation: The effect of local attraction is commonly observed in compass surveying, where the presence of external magnetic influences can lead to inaccuracies in directional measurements and alignments during surveying operations.

Explanation: The angle formed between the true meridian and the magnetic meridian is known as the magnetic declination or simply the declination, an important concept in compass surveying that influences the accuracy and reliability of directional measurements and alignments.

Explanation: Magnetic declination can vary from one location to another, indicating changes in the angle between the true meridian and the magnetic meridian, an essential consideration in compass surveying for ensuring accurate and reliable directional measurements and alignments.

Explanation: The magnetic north is indicated by a magnetic compass, which aligns itself with the Earth’s magnetic field, helping in determining directions.

Explanation: The magnetic declination is the angular difference between the magnetic bearing and the true bearing. In this case, 65° – 45° = 20°W (West) indicates a magnetic declination of 20°W.

Explanation: A negative declination indicates that the magnetic meridian lies to the west of the true meridian. Magnetic declination can be either positive (east) or negative (west) depending on the relationship between the two meridians.

Explanation: In the southern hemisphere, the magnetic bearing of the sun at noon indicates a magnetic declination of 30°E (East) because the sun is to the north of the true north direction.

Explanation: Isogonic lines are lines on the Earth’s surface that connect points with the same magnetic declination, indicating regions with consistent magnetic declination values.

Explanation: The main important variation in declination is the secular variation, which refers to long-term changes in magnetic declination that occur over many years.

Explanation: Secular variation is significant because it involves relatively large and long-term changes in magnetic declination, and the compass needle may reverse its direction due to these variations.

Explanation: Diurnal variation depends on the locality, time of day, and even seasonal factors, making it a complex variation in magnetic declination.

Explanation: To calculate the true bearing when the declination is to the east, you add the magnetic declination to the magnetic bearing.

Explanation: The true bearing is calculated by adding the magnetic declination to the compass bearing, resulting in S53°0’E in this case.

Explanation: The included angle ABC can be found by subtracting the bearing of AB from the bearing of BC (270° – 200° = 70°). However, this is just the angular difference, so the included angle is 180° – 70° = 110°.

Explanation: The true bearing is calculated by adding the magnetic declination to the reduced bearing, resulting in S46°0’E in this case.

Explanation: The initial and foremost work during traversing with a compass is reconnaissance, which involves evaluating the survey area, selecting station locations, and planning the survey operations.

Explanation: A traverse survey can be plotted using various methods, including rectangular coordinates, plotting by tangents, paper protractor, included angles, parallel meridian method, and plotting by chords, depending on the specific requirements of the survey.

Explanation: When the needle of a compass is sluggish (slow to respond or sticky), it indicates an instrumental error, often associated with the compass itself.

Explanation: A sluggish needle in a compass is typically categorized as an instrumental error rather than a natural error. Natural errors include variation in magnetic declination, local attraction, and irregular variation.

Explanation: To ensure that a station is free from local attraction, the fore and back bearings of the line should differ by exactly 180°. This ensures that the effects of local attraction are accounted for and canceled out during the surveying process.

Explanation: The declination can be calculated by finding the difference between the magnetic and true bearings, resulting in a declination of 10°E in this case.

Explanation: If both stations A and B are equally affected by local attraction in different directions, the difference between the forebearing and back bearing of line AB could be 180°, 200°, or 220°, depending on the specific circumstances.

Explanation: When setting up survey stations during traversing with a compass, it is essential that the stations are positioned such that the line joining them is near the objects to be located. This ensures that the survey is conducted accurately and efficiently, with the key features adequately covered.

Explanation: A maximum permissible difference of 15 minutes (15′) is allowed between the fore bearing and back bearing of a line. This tolerance helps ensure the accuracy of the survey measurements while accounting for minor human errors.

Explanation: The plane of sight not being vertical is not typically considered a personal error in surveying. Instead, it often falls under instrumental error or other factors related to the equipment used in the surveying process.

Explanation: When the needle of a compass is truly magnetic and not sluggish, it will come to rest in alignment with the magnetic meridian, indicating the direction of magnetic north at that location.

Explanation: If the sights of a surveying instrument are vertical, it ensures that the eye vane, object vane, and string are parallel and lie along the same line, which is crucial for accurate measurements during the surveying process.

Explanation: Adjusting the needle in a compass involves ensuring its sensitivity, balancing it properly, and straightening it both vertically and horizontally, allowing for accurate readings and minimizing errors during surveying.

Explanation: A diagonal eyepiece in surveying instruments is typically equipped with a reflecting prism or a mirror fitted at 45° with the axis of the telescope, enabling comfortable viewing angles and convenient measurements.

Explanation: The acceptable angular error of closure or summation error should not exceed 15 times the square root of the number of stations (N) or sides in the survey. This criterion helps maintain the overall accuracy of the survey measurements.

Explanation: A level line is both parallel to the mean spherical surface of the earth and normal to the plumb line at all points, ensuring that it aligns with the Earth’s gravitational field and the overall curvature of the planet.

Explanation: The surface of zero elevation around the Earth, which accounts for the irregularities and curvature of the planet, is known as the geoid surface, serving as a reference for measurements and calculations related to elevation and gravity.

Explanation: The line normal to the plumb line, indicating the direction of gravity, is referred to as the vertical line. It is perpendicular to the horizontal plane and assists in defining the orientation and alignment of structures and features.

Explanation: A still lake provides an example of a level surface, as its surface remains relatively unaffected by external forces and disturbances, maintaining a consistent horizontal plane within the boundaries of the lake.

Explanation: In the context of surveying, the place where the reading is taken is known as the station. It serves as a specific location from which observations and measurements are made to gather data for mapping and other purposes.

Explanation: Leveling primarily involves measuring the height differences and variations between different points on the Earth’s surface, allowing for the determination of relative elevations and the creation of accurate topographic maps and profiles.

Explanation: Crosshairs in a surveying telescope are typically fitted in the optical center of the eyepiece, providing a reference for aligning and measuring various points and features within the surveying field of view.

Explanation: A datum line serves as an arbitrarily assumed level line that acts as a reference for measuring vertical distances and elevations during the surveying process, ensuring standardized calculations and consistent measurements.

Explanation: The primary differences between a level line and a horizontal line include the fact that a level line is normal to the plumb line and can be curved, whereas a horizontal line may not necessarily be normal to the plumb line and is always straight.

Explanation: A benchmark (BM) serves as a point of known elevation in the surveying process, providing a reference for determining and calculating the elevations of other points and features within the survey area.

Explanation: A staff reading taken on a benchmark, known elevation, or change point during the surveying process is known as a back sight. This reading serves as a reference for calculating the relative elevations of other points within the survey area.

Explanation: In the context of leveling, the station where both the back sight and foresight readings are taken is known as the change point, indicating the location where the elevation differences are measured and recorded.

Explanation: A benchmark is a relatively fixed point with a known elevation above the datum, serving as a reference for calculating the elevations of other points and features within the survey area.

Explanation: Differential leveling is an essential operation in surveying that involves determining the relative elevations of different points on the Earth’s surface. It helps in creating accurate elevation profiles and contour maps for various applications and projects.

Explanation: A dumpy level employs a combination of lenses to achieve multiple objectives, including providing a clear and distinct image, shortening the image for ease of use, and allowing for accurate readings even in low-light conditions.

Explanation: In a dumpy level, the image of the objectives should ideally lie in the plane of cross hairs, ensuring that the cross hairs align accurately with the target, thereby enabling precise measurement and leveling.

Explanation: Aplanation refers to the absence of spherical aberration in an optical instrument, ensuring that all parts of an object at various distances from the lens are brought into focus on the same image plane.

Explanation: Achromation refers to the correction of chromatic aberration in optical systems, ensuring that various wavelengths of light are brought to the same focal point, resulting in clearer and more accurate imaging.

Explanation: The magnification of a telescope depends on the ratio of the focal length of the objective lens to that of the eyepiece, determining the level of magnification achieved by the optical instrument.

Explanation: In an internal focusing type of telescope, a double concave lens is used as the negative lens to facilitate the adjustment of focus within the optical system.

Explanation: The movement of the concave lens within the internal focusing type of telescope enables the adjustment of focus, allowing the user to achieve a clear image of the target or object being observed or measured.

Explanation: The sensitivity of the bubble tube in a leveling instrument can be enhanced by increasing the diameter of the tube, allowing for more precise and accurate measurements of the instrument’s horizontal orientation.

Explanation: The level tube, which is an essential component of a leveling instrument, can be filled with various fluids such as ether, chloroform, or synthetic alcohol to aid in establishing a horizontal line of sight for accurate measurements and leveling operations.

Explanation: The constant size of the bubble in a level tube is maintained by ensuring that the upper wall of the tube has a relatively large radius, preventing any distortion or change in the bubble’s dimensions during the leveling process.

Explanation: The sensitivity of a bubble tube is affected by changes in temperature, with an increase in temperature leading to a decrease in sensitivity, potentially impacting the precision and accuracy of the leveling instrument’s readings.

Explanation: The sensitivity of a level tube can be expressed through various parameters, including the length of the tube, the radius of the tube, and the length of the bubble within the tube, collectively influencing the precision and performance of the leveling instrument.

Explanation: The dumpy level is employed in surveying projects that require a significant number of observations to be taken from a single level position, facilitating efficient and accurate measurements over a large area or site.

Explanation: Automatic levels offer several advantages, including high precision, reduced susceptibility to external influences, and improved comfort during use, making them versatile tools suitable for various surveying applications and projects.

Explanation: The height of instrument method in surveying is known for being less tedious, more rapid in execution, and involving fewer calculations compared to other leveling techniques, thereby enhancing the overall efficiency and productivity of the surveying process.

Explanation: The height of instrument method of leveling is recognized for its speed and simplicity, offering a quick and less tedious approach to establishing elevations compared to the more comprehensive and time-consuming rise and fall method.

Explanation: The rise and fall method of leveling serves as a comprehensive check on all the readings taken during the survey, including the back sight, fore sight, and any intermediate sights, ensuring the accuracy and reliability of the surveying data and results.

Explanation: The rise and fall method of leveling offers several advantages, including providing a check on the intermediate readings, being well-suited for differential and check leveling tasks, and being applicable for important and critical surveying projects.

Explanation: To obtain the correct reading on the level staff, the observed reading must be adjusted by accounting for any deviation from the vertical position. In this case, the corrected reading would be 3.83m – 0.15m = 3.827m, ensuring the accuracy of the measured elevation.

Explanation: The observed reading on the leveling staff needs to be adjusted to account for any displacement or offset from the original ground level. By subtracting the given offset of 0.150m from the observed reading of 3.545m, the corrected value is 3.395m.

Explanation: To obtain the correct reading, the offset of 0.125m from the original ground level needs to be added to the observed reading of 3.525m, resulting in a corrected value of 3.65m.

Explanation: During the leveling of the instrument, the vertical axis is aligned to be truly vertical, ensuring the accuracy and reliability of the leveling process.

Explanation: In the case of taking leveling staff readings, it is the responsibility of the staff man to hold the staff and ensure that accurate measurements are obtained by the instrument man.

Explanation: Instrumental error in leveling can arise from various factors, including imperfect adjustments, sluggish bubbles, and any unintended movement of the objective slide, all of which contribute to measurement inaccuracies.

Explanation: Natural error in leveling can occur due to factors such as wind vibration, atmospheric refraction, and temperature fluctuations, which can impact the precision and reliability of the leveling measurements.

Explanation: The process of permanent adjustment involves establishing and maintaining a consistent and fixed relationship between the fundamental axes of the leveling instrument, ensuring accurate and reliable measurements over time.

Explanation: For accurate leveling measurements, the line of collimation should be parallel to the bubble axis, ensuring that the leveling instrument is correctly aligned and the measurements are precise.

Explanation: In specific types of leveling instruments such as Y levels, Cooke’s levels, and Cushing levels, the line of collimation needs to align with the axis of the telescope to ensure accurate and reliable measurements.

Explanation: In a dumpy level that is perfectly adjusted, the horizontal crosshair should lie in a plane perpendicular to the vertical axis, ensuring that the line of sight remains accurate and horizontal.

Explanation: The two-peg method is specifically employed to verify and ensure the parallelism between the line of collimation and the axis of the bubble tube in the leveling instrument, guaranteeing accurate and reliable leveling measurements.

Explanation: Reciprocal leveling is utilized in situations where it is not feasible to set up the level midway between two points. It enables the measurement of the elevation difference between these points, ensuring accurate leveling data.

Explanation: Fly leveling is commonly employed for carrying out the reconnaissance of an area, providing rapid and efficient measurements of the terrain’s elevation, essential for various surveying and construction projects.

Explanation: The accuracy demanded in precise leveling typically falls within the range indicated, with the value depending on the total distance of the level line in kilometers (K), ensuring precise and reliable elevation measurements.

Explanation: The formation level represents the level to which the earthwork is to be carried out during construction, serving as a critical reference point for the completion of the project’s structural elements and surfaces.

Explanation: When the formation level is lower than the ground level, the disparity between the two at any specific point provides the depth of cutting necessary to achieve the desired formation level, aiding in the planning and execution of the construction project.

Explanation: Reciprocal leveling helps eliminate both the error due to curvature and the collimation error, ensuring the accuracy and reliability of the leveling measurements conducted between various points on the Earth’s surface.

Explanation: The curvature of the Earth affects the perception of objects, making them appear lower than their actual height, a critical consideration in surveying and leveling to ensure accurate measurements and calculations.

Explanation: The correction for refraction is computed using the formula 0.0112 d^2m, where d represents the distance between the points. This correction factor accounts for the optical refraction that can affect leveling measurements.

Explanation: When the distance between two points A and B is 1km, the combined correction for curvature and refraction is 0.0673m, compensating for the effects of the Earth’s curvature and optical refraction on the leveling measurements.

Explanation: The sensitivity of the bubble tube, denoting the angular value of one division of the bubble, is expressed as S/D radians, where S represents the sensitivity of the bubble tube and D signifies the angular value of one division of the bubble.

Explanation: Personal error in leveling can stem from various factors, including careless leveling of the instrument, the bubble not being centered, and the staff not being held vertically, all of which contribute to inaccuracies in the leveling measurements.

Explanation: Leveling across a river is typically accomplished using the reciprocal leveling method, which enables the measurement of the elevation differences between points on either side of the river, ensuring accurate and precise leveling data.

Explanation: In trigonometrical leveling, the combined correction is computed using the formula (1-2m) d^2 / 2R, where d represents the distance between the points, and m is the coefficient of refraction, considering the effects of refraction in the leveling measurements.

Explanation: Bench marks are typically fixed using the spirit leveling method, ensuring that accurate and reliable reference points are established for the measurement of elevations in the surveying process.

Explanation: In the leveling process, the final reading is always referred to as the foresight, indicating the last measurement taken at a specific point, helping to determine the elevation of the location.

Explanation: Tilting levels are commonly utilized for precise leveling applications, ensuring accurate and reliable measurements of elevations and height differentials, critical for various surveying and construction projects.

Explanation: Geodetic surveys typically employ precise leveling techniques, ensuring the accurate determination of elevations and the creation of precise topographic maps and surveys for large-scale geographic areas.

Explanation: A compensator is specifically utilized in an automatic level to ensure that the line of sight remains perpendicular to the vertical axis, contributing to the accuracy and stability of the leveling instrument during measurements.

Explanation: When conducting leveling across a hill, it is essential to set up the level on the side of the hill, ensuring accurate and reliable measurements of the elevation changes across the terrain’s varying topography.

Explanation: A level surface is not directly parallel to any specific surface, instead representing an imaginary surface that is perpendicular to the direction of gravity, aiding in the measurement and determination of elevations during surveying and construction.

Explanation: The surface perpendicular to the direction of gravity is referred to as the level surface, denoting an imaginary surface that aids in measuring elevations and height differentials accurately during various surveying and construction activities.

Explanation: The Philadelphia rod is classified as a type of telescopic staff, an essential tool used in surveying to accurately measure and record vertical distances and elevations during leveling and other surveying operations.

Explanation: The correction for curvature applied to staff reading is computed using the formula -d² / 2R, where d represents the distance between the points being measured, and R signifies the radius of the Earth, accounting for the effects of the Earth’s curvature on the leveling measurements.

Explanation: The curvature correction applied to staff readings is typically negative, accounting for the downward curvature effect, while the refraction correction is positive, compensating for the bending of light rays during the leveling measurements.

Explanation: If the level tube is out of adjustment by an angle e, when the telescope is rotated through 180°, it results in an effective misalignment of 2e, indicating that the error is doubled when the telescope is rotated.

Explanation: The imaginary line passing through the intersection of crosshairs and the optical center of the object is referred to as the line of collimation, serving as a critical reference line for ensuring the accurate alignment and targeting of the surveying instrument.

Explanation: The statement about parallax error is the odd one out as parallax error cannot be completely eliminated solely by the absence of change in the staff reading when the eye is moved up and down. It can be minimized by careful adjustments and focusing techniques during surveying operations.

Explanation: “Cross-sectioning” and “Longitudinal sectioning” are terms commonly associated with profile leveling, describing the techniques used to create cross-sectional and longitudinal views of the terrain, aiding in the visualization and analysis of the landscape for various surveying and construction purposes.

Explanation: An invert is typically taken when the point being measured is above the line of sight, indicating the point at which an architectural element, such as a pipe or a culvert, intersects the inside bottom of the structure, serving as a critical reference point for construction and design purposes.

Explanation: When the instrument is shifted during the leveling process, the foresight readings are typically taken after the instrument is moved to a new location. In this case, the foresight readings are recorded after the 2nd, 6th, and 10th readings.

Explanation: In the case of the leveling process, the foresight readings are taken after the instrument has been shifted to a new position. Here, the foresight readings are recorded after the 5th, 10th, and 15th readings.

Explanation: The difference in staff readings between neighboring pegs along the proposed road indicates the gradient of the road. In this case, the staff readings suggest a rising gradient of 1 in 100 for the proposed road.

Explanation: A French cross-staff is capable of setting angles of either 45° or 90° during the surveying process, providing flexibility in measuring and setting angles for various applications.

Explanation: The staff intercept is the difference in staff readings taken from consecutive horizontal crosshairs during the leveling process. In this case, the staff intercept is 0.4, computed as the difference between 1.0 and 0.6.

Explanation: When the total fall (Σfall) is recorded as 0 in a survey, it suggests that the ground is continuously rising, indicating that there is no net change in elevation or a negative gradient along the survey path.

Explanation: When the total rise (Σrise) is recorded as 0 in a survey, it suggests that the ground is continuously falling, indicating that there is no net change in elevation or a positive gradient along the survey path.

Explanation: The reduced level (RL) of station B can be calculated by adding the benchmark’s height to the back sight reading and subtracting the foresight reading. In this case, the RL of station B is 499 m.

Explanation: The staff reading of the intermediate sight (IS) can be calculated by subtracting the RL of the benchmark from the given RL of IS. In this case, the staff reading of IS is 2.5 m.

Explanation: The reduced level of the base of the pillar can be determined by subtracting the staff reading at the base of the pillar from the reduced level of the line of collimation. In this case, the reduced level of the base of the pillar is 48.85 m.

Explanation: The reduced level (RL) of point A can be calculated by adding the benchmark’s height to the backsight reading and subtracting the foresight reading. In this case, the RL of point A is 400.10 m.

Explanation: The reduced level (RL) of the collimation line can be calculated by adding the backsight (BS) staff reading to the RL of the benchmark. In this case, the RL of the collimation line is 105.35 m.

Explanation: The reduced level (RL) of point B can be calculated by adding the elevation of point A to the backsight (BS) reading at point A and subtracting the foresight (FS) reading at point B. In this case, the RL of point B is 90 m.

Explanation: “Bearing” is a term associated with the field of compass surveying and navigation, indicating the direction or horizontal angle of a line, whereas the other terms are directly related to leveling operations.

Explanation: Abney levels are commonly used in the survey of gravity water supply systems due to their ability to measure angles of slope and elevation accurately, making them suitable for various topographic surveying applications.

Explanation: The height of the instrument (HI) is calculated by adding the reduced level (RL) of the benchmark to the backsight (BS) reading, indicating the elevation of the instrument above the benchmark point during the leveling process.

Explanation: Plane table surveying involves a method where fieldwork and plotting are conducted simultaneously, allowing for the immediate representation of survey data on the plane table, facilitating the creation of accurate maps and plans.

Explanation: Plane table surveying is a graphical method that involves the simultaneous process of conducting fieldwork and plotting, enabling surveyors to directly represent survey data on the plane table during the surveying operation.

Explanation: Setting up the plane table involves the combined operations of leveling and centering the table accurately, ensuring that the table is positioned correctly and securely before commencing the surveying and mapping activities.

Explanation: Plane table surveying is advantageous compared to other survey methods because it allows surveyors to immediately plot data in the field, reducing the likelihood of missing critical details and ensuring the accuracy and completeness of the survey information.

Explanation: The plane table survey, while effective for simultaneous fieldwork and plotting, has several drawbacks, including being heavy and awkward to carry, unsuitable for use in wet climates, and potential difficulty in accurately transferring details to a different scale.

Explanation: Centering involves precisely positioning the plane table over a station so that the point plotted on the table coincides exactly with the corresponding station on the ground. This ensures accurate plotting and mapping during the survey.

Explanation: Orientation in plane table surveying involves maintaining the table’s position at successive stations so that it is parallel to the position it occupied at the previous station, ensuring that the table remains aligned and accurate during the survey process.

Explanation: In plane table surveying, the intersection method is commonly used to gather details and plot points that are inaccessible or difficult to reach directly, allowing surveyors to determine locations accurately by intersecting lines of sight from known stations.

Explanation: In the intersection method of plane tabling, surveyors typically set up two stations to establish intersecting lines of sight, enabling them to determine the location of points that may not be directly accessible from a single station.

Explanation: Resection in plane table surveying is a method used to locate the instrument station precisely, enabling surveyors to establish their position accurately based on visible points and details in the survey area.

Explanation: The two-point problem in plane table surveying involves determining the position of the plane table based on two visible and well-defined points, allowing surveyors to accurately establish their location without requiring a direct line from the preceding station to the instrument station.

Explanation: The two-point problem in plane table surveying is considered more laborious compared to the three-point problem, although it may be less accurate. This method requires additional computations and observations to establish the location of the plane table accurately.

Explanation: The three-point problem in plane table surveying can be solved using various methods, including the tracing paper method, graphical method, or trial and error method, depending on the available data and survey requirements.

Explanation: The three-point problem in plane table surveying focuses on determining the position of the plane table based on observations from three visible points in the survey area, enabling surveyors to accurately plot and map points on the table.

Explanation: The standard size of a plane table typically measures 600 x 750mm, providing surveyors with a suitable surface area for conducting fieldwork and accurately plotting data during the surveying process.

Explanation: The quadrantal bearing of a line is determined using a surveyor’s compass, which is specifically designed to measure the direction or horizontal angle of a line accurately, allowing surveyors to establish bearings and orientations during the survey process.

Explanation: The strength of the fix in plane table surveying is determined by the accuracy in locating the position of the instrument station through observations taken from three stations, ensuring precise positioning and reliable data for mapping and plotting purposes.

Explanation: A good fix in plane table surveying is achieved when the station is within the great triangle, the middle station is farther than the other two stations, and the angle subtended between the stations is not very small, ensuring accurate and reliable survey data.

Explanation: A poor fix in plane table surveying is determined when the station is located near the great circle, potentially leading to inaccuracies and inconsistencies in the survey data, affecting the overall reliability of the survey results.

Explanation: The strength of fix’ is considered poor when the station is located on the great circle, potentially leading to difficulties in accurately positioning the instrument station and affecting the overall reliability and accuracy of the survey data.

Explanation: Both the two-point problem and three-point problem in plane table surveying are methods used for both orientation and resection, enabling surveyors to accurately determine the position of the instrument station based on visible points in the survey area.

Explanation: The resection by a two-point problem in plane table surveying generally requires more labor compared to the three-point problem, although it may take less time. This method may be less accurate due to the limited number of points used for calculations.

Explanation: When the plane table is not perfectly horizontal in a direction perpendicular to the alidade, the line of sight remains parallel to the fiducial edge only for horizontal sights, potentially affecting the accuracy and reliability of the survey data for inclined sights.

Explanation: When orienting a plane table without two accessible points, the commonly adopted method is the two-point problem, which allows surveyors to determine the position of the instrument station based on observations from two visible and well-defined points, ensuring accurate and reliable survey data for mapping and plotting purposes.

Explanation: Personal errors in surveying typically refer to mistakes made by the surveyor during the measurement process. Issues such as the table not being perfectly leveled, centered, or clamped are considered personal errors that can affect the accuracy of the survey data.

Explanation: In plane table surveying, the radiation method involves setting up the plane table at one station to observe and record details in the surrounding area, enabling surveyors to map and plot points without the need for additional stations.

Explanation: In hilly areas, the intersection method is considered the most suitable for plotting during plane table surveying. This method allows surveyors to determine the location of points accurately, even when the terrain is challenging or uneven.

Explanation: The intersection method is preferred over radiation when points in the survey area are inaccessible. This method enables surveyors to accurately determine the position of points by observing intersecting lines of sight from visible and accessible stations.

Explanation: Resection is not a method of plane tabling. Instead, it is a method used for determining the position of the instrument station by taking observations from known points in the survey area, enabling surveyors to establish their location accurately.

Explanation: The plumbing fork is an instrument used for centering the plane table accurately during the surveying process, ensuring that the table is positioned precisely over the station for accurate mapping and plotting.

Explanation: The orientation of the table in plane table surveying can be done using a combination of methods, including the magnetic needle and back sighting, ensuring that the table is accurately positioned and aligned during the survey process.

Explanation: The fiducial edge is the working edge of the alidade in plane table surveying. This edge is used for sighting and observing points in the survey area, enabling surveyors to accurately determine the position and location of points on the table.

Explanation: The working edge of the alidade is known as the fiducial edge. This edge is specifically designed for sighting and observing points in the survey area, ensuring precise measurements and accurate plotting during the survey process.

Explanation: The telescopic alidade is a plane table instrument used for horizontal and vertical measurement without the need for chaining. This instrument enables surveyors to take accurate measurements and observations during the survey process.

Explanation: The triangle formed by joining the positions of the known points on a plane table survey is known as the great triangle. This triangle enables surveyors to establish accurate locations and measurements for plotting and mapping purposes.

Explanation: The area of the triangle formed by joining three corner points is always less compared to the circle formed by the same three points. This relationship between the triangle and the circle is a fundamental concept in plane table surveying.

Explanation: Theodolite is an essential surveying instrument used for measuring various angles, including horizontal angles, vertical angles, and deflection angles, enabling surveyors to establish accurate measurements and observations during the survey process.

Explanation: The process of turning the telescope about the horizontal axis in a vertical plane by a complete revolution is known as reversing, transiting, or plunging, depending on the specific context and application in the surveying process.

Explanation: The process of turning the telescope about the vertical axis in a horizontal plane is known as swinging. This movement enables surveyors to observe and measure various points and angles accurately during the survey process.

Explanation: The leveling head of a transit theodolite typically consists of various components, including parallel plates, a tribarch plate, leveling screws, and other mechanisms designed to ensure the stability and accuracy of the instrument during the surveying process.

Explanation: The leveling head serves multiple functions in a transit theodolite, including attaching the theodolite to the tripod, providing a bearing for the outer hollow spindle, and offering a means of leveling the instrument accurately during the survey process.

Explanation: The size of a theodolite is typically specified by the diameter of the lower plate. This specification helps determine the overall dimensions and characteristics of the theodolite, enabling surveyors to choose the appropriate instrument for specific surveying tasks.

Explanation: A 20 cm theodolite refers to the diameter of the lower plate of the theodolite. This specification helps identify the size and dimensions of the instrument, ensuring that the theodolite is suitable for specific surveying tasks and measurements.

Explanation: The projection of a line on a plane parallel to the meridian is known as latitude in surveying terminologies. This concept helps determine the specific positioning and location of points in the survey area relative to the equator, enabling accurate mapping and plotting during the survey process.

Explanation: The projection of a line on a plane perpendicular to the meridian is referred to as “departure” in surveying. This concept helps determine the north-south position of a point relative to a specific reference point.

Explanation: When dealing with a telescopic alidade, the necessary adjustments include ensuring that the line of collimation is perpendicular to the axis of the telescope, that the horizontal axis is parallel to the alidade rule, and that the bubble line of the telescope level is parallel to the plane of collimation.

Explanation: The outer spindle attached to the lower plate in a transit theodolite is termed the “scale plate.” It is a critical component that aids in accurate angle measurement and reading during the surveying process.

Explanation: In a theodolite, the line passing through the intersection of the horizontal and vertical crosshairs and the optical center of the object glass is called the “line of collimation.” This line is essential for accurate sighting and measurement during surveying operations.

Explanation: The fundamental lines of transit of the theodolite include the horizontal axis and the line of collimation, as well as the vertical axis, and the axes of plate levels and the bubble line of the telescope level. These lines are crucial for the proper functioning and accurate measurement of the theodolite.

Explanation: The upper plate of the theodolite is a critical component attached to the inner spindle, often referred to as the vernier plate. It features two verniers 180° apart for precise and accurate reading of horizontal angles. It is also known as the alidade of the theodolite.

Explanation: When the image formed by the objective of the telescope is not in the plane of the crosshairs, it results in a condition known as “parallax.” This phenomenon can lead to errors in sighting and measurement, and it needs correction to ensure accurate surveying results.

Explanation: A straight line tangential to the longitudinal curve of the level tube at its center is referred to as the “bubble line.” This line is critical in leveling instruments to ensure accurate measurements and assessments during surveying tasks.

Explanation: The trunion axis or transverse axis refers to the axis around which the telescope can be rotated in a vertical plane. It plays a crucial role in enabling the movement and orientation of the telescope during surveying tasks.

Explanation: A telescope is considered normal when the bubble of the telescope is up, and the face of the vertical circle is to the left. This configuration ensures proper orientation and accurate readings during surveying operations.

Explanation: The process of bringing the vertical circle to the right of the observer is known as “changing face.” This adjustment is essential to ensure accurate readings and observations during the surveying process.

Explanation: Parallax can be eliminated by adjusting both the eyepiece and the objective. Focusing both components appropriately ensures that the image is correctly aligned with the crosshairs, reducing errors and improving the accuracy of surveying measurements.

Explanation: The ‘SPIRE TEST’ is utilized in the permanent adjustment of theodolites to ensure the accurate alignment and adjustment of the horizontal axis. This procedure is crucial for maintaining the precision and reliability of the instrument during surveying operations.

Explanation: The error eliminated by taking the mean of both face observations is the error due to the line of collimation not being perpendicular to the horizontal axis. By considering both face observations, this error can be minimized to enhance the accuracy of the measurements.

Explanation: A traverse deflection angle is the difference between the included angle and 180°. It helps in determining the direction and extent of deviation from the expected path, aiding in accurate plotting and mapping during surveying tasks.

Explanation: When the included angle is greater than 180°, the deflection angle is considered to be right-handed or positive. This understanding is crucial in interpreting and correcting deviations in surveying calculations.

Explanation: If the included angle is less than 180°, the deflection angle is considered to be left-handed or negative. Understanding this distinction is vital in accurately assessing and rectifying deviations in surveying measurements.

Explanation: The difference between the sum of the measured angles and the theoretical sum of the angles of a closed traverse is known as the angular closing error. This value is essential in evaluating the accuracy and closure of the traverse during surveying operations.

Explanation: The difference between the two bearings of the last line as observed at the first and the last station of a traverse is termed the closing error in bearing. This measure is crucial in evaluating the accuracy of the traverse and ensuring precise adjustments in surveying computations.

Explanation: The bearing of the traverse line can be calculated using both the included angle method and the deflection angle method. These techniques aid in determining the orientation and direction of the traverse line, facilitating accurate mapping and plotting during surveying tasks.

Explanation: Bowditch’s rule is applied to a closed traverse for the adjustment of closing error. This rule helps in rectifying any discrepancies in the closing error, ensuring the accurate closure and precision of the traverse during surveying operations.

Explanation: The included angles of the theodolite traverse are generally measured clockwise from the back station. This approach helps in maintaining consistency and uniformity in the measurement process, facilitating accurate calculations and adjustments during surveying tasks.

Explanation: In a closed traverse by included angles, the sum of measured interior angles should be equal to (2N-4) right angles. This relationship ensures the accuracy and closure of the traverse, aiding in precise calculations and adjustments during surveying activities.

Explanation: Azimuth (direct angles) is an angle measured in the clockwise (c.w.) direction. This approach helps in determining the orientation and direction of the celestial or terrestrial points, facilitating accurate mapping and navigation during surveying tasks.

Explanation: The direction of the closing error is given by tan^-1 ΣD/ΣL, where ΣD represents the sum of the deflection angles, and ΣL represents the sum of the lengths. This calculation helps in understanding the extent and direction of any discrepancies, aiding in accurate adjustments during surveying activities.

Explanation: The closing error is given by the square root of the sum of the squares of the lengths (ΣL) and deflection angles (ΣD). This calculation helps in quantifying any discrepancies and errors, facilitating accurate adjustments and corrections during surveying operations.

Explanation: In a traverse, the algebraic sum of the deflection angles, considering the right-hand deflection angles as positive and left-hand deflection as negative, should be equal to 360°. This relationship ensures the balance and accuracy of the traverse measurements, aiding in precise adjustments and computations during surveying tasks.

Explanation: If a traverse consists of six sides, then the sum of the external angles must be 1440°. Understanding this relationship helps in ensuring the accuracy and completeness of the traverse measurements, aiding in precise calculations and adjustments during surveying operations.

Explanation: In a closed traverse, the algebraic sum of the deflection angles is 360°. This understanding is crucial in verifying the accuracy and closure of the traverse measurements, aiding in precise adjustments and computations during surveying tasks.

Explanation: In a closed traverse, the closing error should not be more than √N times the least count of the instrument. Adhering to this constraint ensures the accuracy and reliability of the traverse measurements, facilitating precise adjustments and computations during surveying operations.

Explanation: The angular and linear measurement of the part of the traverse can be verified by using cut off lines. This technique helps in ensuring the accuracy and precision of the measurements, facilitating reliable surveying assessments.

Explanation: The distance between terminal points computed from a subsidiary traverse run between them is referred to as the traverse base. This value serves as a crucial reference for various surveying calculations and adjustments, aiding in accurate mapping and plotting.

Explanation: The maximum number of omitted measurements that can be calculated from latitudes and departures of a closed traverse is two. Understanding this limit is essential in ensuring the completeness and accuracy of surveying assessments and computations.

Explanation: Axis method of traverse correction is employed when the angles are measured very accurately. This approach helps in rectifying any discrepancies or errors in the surveying measurements, ensuring precise and reliable results.

Explanation: When the sum of northing exceeds the sum of southing by 2m and the sum of easting exceeds the sum of westing by 2m, the resulting closing error is 2√2 m. Understanding this relationship is crucial in assessing and rectifying discrepancies during surveying operations.

Explanation: The perpendicular distance of the midpoint of the line from the reference meridian is termed as the meridian distance. This value plays a significant role in surveying calculations, aiding in accurate positioning and mapping during various surveying tasks.

Explanation: Right face and left face readings are taken to eliminate the error of the trunnion axis not being exactly horizontal. This approach ensures the accuracy and precision of the surveying measurements, minimizing errors for reliable results.

Explanation: Theodolite traverse is plotted more accurately by using independent coordinates of each section. This method facilitates precise plotting and mapping, ensuring the reliability and accuracy of the surveying results.

Explanation: In a theodolite, the staff readings for upper, middle, and lower crosshairs are 1.4, 0.9 & 0.4, respectively. Given the height of the tower as 100m, the horizontal distance between the instrument station and the base of the tower is 100m.

Explanation: Staff intercept refers to the difference between the top and bottom reading on a staff. This value is crucial in determining the height differences and elevations during various surveying tasks, ensuring accurate measurements and assessments.

Explanation: The main difference between theodolite and level is that the level cannot measure horizontal angles, while the theodolite can measure horizontal angles. Understanding this distinction is crucial in selecting the appropriate instrument for specific surveying tasks.

Explanation: When the angular and linear measurements are equally precise in traversing, the balancing of the traverse is done using Bowditch’s rule. This technique ensures the accuracy and precision of the traverse, minimizing discrepancies and errors in surveying calculations.

Explanation: A leveling station is a point where the level staff is held during the surveying process. Understanding this concept is essential in ensuring accurate measurements and assessments of elevations and height differences during various surveying tasks.

Explanation: Angular surveying in which both the horizontal and vertical positions of a point are obtained by optical means is known as tacheometry. This method facilitates accurate and precise measurements and assessments in surveying tasks, aiding in reliable mapping and plotting.

Explanation: Tacheometry is adopted in areas where obstacles and undulations exist, making traditional surveying methods challenging. This technique enables accurate measurements and assessments, even in complex and uneven terrains, facilitating reliable mapping and plotting.

Explanation: The method of tacheometry in which the stadia hair intercept is fixed is known as the fixed hair method. This approach aids in precise and reliable measurements during surveying tasks, ensuring accurate calculations and assessments.

Explanation: The stadia hairs are not used in the tangential hair method of tacheometry. Understanding this distinction is crucial in selecting the appropriate method for specific surveying tasks, ensuring accurate and reliable measurements and assessments.

Explanation: The method of tacheometry in which the observation is made with stadia wires with a variable interval is known as the movable hair method. This technique facilitates precise and flexible measurements during surveying tasks, ensuring reliable mapping and plotting.

Explanation: The number of horizontal cross wires in a stadia diaphragm is three. This feature enables accurate and reliable measurements during tacheometry, ensuring precise calculations and assessments in various surveying tasks.

Explanation: The horizontal distances obtained by tacheometry are corrected for refraction and curvature to ensure accurate and reliable measurements in various surveying tasks. Understanding and applying this correction is essential in achieving precise mapping and plotting results.

Explanation: The multiplying constant of a tacheometer is represented by f/I. Understanding this constant is crucial in ensuring the accurate and precise measurement of distances in tacheometric surveying.

Explanation: The intercept of a staff is minimal when the staff is held truly normal to the line of sight. This relationship is essential in ensuring accurate and reliable measurements in tacheometric surveying.

Explanation: If the staff is held vertical and the angle of elevation and depression are kept the same, the horizontal distance between the instrument and staff station computed by observation will be the same in both cases. Understanding this principle is crucial in ensuring accurate measurements in tacheometric surveying.

Explanation: In the stadia method, the distance equation is given by the expression D=ks+c, where k is the multiplying factor, s is the staff intercept, and c is the additive constant of the instrument. Understanding this equation is essential in accurate distance calculations in tacheometric surveying.

Explanation: Subtense bar is an instrument used for the measurement of horizontal distance, especially in undulated areas. This tool aids in accurate and reliable measurements in tacheometric surveying, particularly in challenging terrains.

Explanation: For a tacheometer, the additive constant is zero, and the multiplying constant is 100. Understanding these constants is crucial in ensuring accurate and reliable measurements in tacheometric surveying.

Explanation: If the intercept on the vertical staff is observed as 1.5mm from a tacheometer, the horizontal distance between the tacheometer and staff station is 150m. Understanding this relationship is crucial in accurate distance measurements in tacheometric surveying.

Explanation: Given the spacing of crosshairs in a stadia diaphragm of a tacheometer as 1.5mm and the focal length of the objective glass as 30cm, the multiplying constant of the tacheometer is 100. Understanding this constant is essential in accurate distance calculations in tacheometric surveying.

Explanation: In tacheometric survey, the three hair method provides easy reading of the staff. This approach facilitates accurate and reliable measurements in tacheometric surveying, ensuring precise distance calculations and assessments.

Explanation: The statement “anallatic lens is not a concave lens” is wrong. An anallatic lens is a convex lens used to eliminate the additive constant in tacheometry. Understanding the role of the anallatic lens is crucial in ensuring accurate and reliable measurements in tacheometric surveying.

Explanation: The advantage of the anallatic lens is that it makes computation easy as the additive constant in the distance formula vanishes. Understanding this advantage is crucial in accurate and reliable measurements in tacheometric surveying.

Explanation: Given the focal length of the objective glass as 20cm and the distance from the object glass to the trunnion axis as 12cm, the additive constant is 0.32m. Understanding this constant is crucial in accurate distance calculations in tacheometric surveying.

Explanation: An anallatic lens is a convex lens used to remove an additive constant in a tacheometer. Understanding the role of the anallatic lens is crucial in ensuring accurate and reliable measurements in tacheometric surveying.

Explanation: An anallatic lens is provided in a tacheometer to ensure a multiplying constant of 100 and an additive constant of zero. Understanding the purpose of the anallatic lens is crucial in accurate distance measurements in tacheometric surveying.

Explanation: Error in tacheometric surveying can be attributed to various factors, including manipulation, sighting, and natural causes. Understanding these sources of error is crucial in minimizing inaccuracies and ensuring precise measurements in tacheometric surveying.

Explanation: Tacheometric survey is the type of survey in which both horizontal and vertical distances are measured. Understanding this distinction is crucial in selecting the appropriate surveying method for specific tasks and ensuring accurate and reliable measurements.

Explanation: Tacheometry is best suited for surveying in broken grounds, where traditional chaining methods might be impractical. Understanding the suitability of tacheometry in various terrains is crucial in selecting the appropriate surveying method for accurate measurements.

Explanation: In a tacheometer provided with an anallatic lens, the distance between the object glass and the vertical axis is 15 cm. Given the focal length of the objective as 15 cm and that of the anallatic lens as 10 cm, the distance between the two lenses is 17.5 cm. Understanding this relationship is crucial in the accurate functioning of the tacheometer.

Explanation: The revolving of the telescope of a theodolite in a horizontal plane is referred to as swinging. Understanding this motion is crucial in the proper operation and handling of the theodolite during surveying tasks.

Explanation: The longitudinal section of the surface of the bubble tube is circular. Understanding the shape and structure of the bubble tube is crucial in ensuring accurate leveling and measurements during surveying tasks.

Explanation: Contour lines are the imaginary lines on a map connecting points of equal elevation. Understanding the concept of contour lines is essential in representing the three-dimensional topography of an area in a two-dimensional map.

Explanation: The contour interval is the vertical distance between any two consecutive contours on a topographic map. Understanding the contour interval is crucial in accurately representing the elevation changes and topography of an area on a map.

Explanation: The horizontal equivalent is the minimum horizontal distance between any two consecutive contours. Understanding the horizontal equivalent is crucial in accurately representing the topography of an area on a map.

Explanation: The horizontal equivalent of a uniform slope must be equal. Understanding this relationship is essential in accurately representing the topography and slope of an area on a map.

Explanation: The contour interval depends on various factors, including the nature of the ground, the scale of the map, and the purpose and extent of the survey. Understanding these dependencies is crucial in accurately representing the topography of an area on a map.

Explanation: The contour interval is inversely proportional to the scale of the map. Understanding this relationship is crucial in accurately representing the topography of an area on a map with varying scales.

Explanation: Contour gradient refers to an imaginary line lying through the surface of the ground, maintaining a constant inclination to the horizontal. Understanding the concept of contour gradient is essential in accurately representing the slope and inclination of the ground on a map.

Explanation: A series of closed contour lines on a map, with higher values inside, represent a depression. Understanding the representation of depressions on a topographic map is crucial in accurately depicting the features of an area.

Explanation: Contour lines may merge or cross one another on a map in the case of both caves and overhanging ground surfaces. Understanding these intersections is crucial in accurately representing complex topographical features on a map.

Explanation: A series of closely spaced contour lines on a map represent a steep slope. Understanding the representation of slope gradients is crucial in accurately depicting the features and topography of an area on a map.

Explanation: A series of straight, parallel, and widely spaced contours on a map represent an inclined plane surface. Understanding the representation of inclined surfaces is crucial in accurately depicting the topography of an area on a map.

Explanation: Contour lines are perpendicular to both the ridge line and the valley line. Understanding the orientation of contour lines is crucial in accurately representing the features and topography of an area on a map.

Explanation: The tacheometric method is a more suitable method for preparing the contour map of a hill. Understanding the applicability of different surveying methods is crucial in accurately representing the topography of various terrains on a map.

Explanation: The representation of the general topography of a very flat terrain is possible only by giving spot levels to salient features of a close interval. Understanding the mapping techniques for various terrains is crucial in accurately representing the features of an area on a map.

Explanation: The direct method of contouring is a very slow method, but it is the most accurate and is suitable for contouring a small area. Understanding the applicability and limitations of different contouring methods is crucial in accurately representing the features of an area on a map.

Explanation: The contour interval, within the limits of a map, must be kept constant. Ensuring a constant contour interval is crucial in accurately representing the topography and features of an area on a map.

Explanation: Two contour lines having the same elevation can unite together. Understanding the behavior and characteristics of contour lines is crucial in accurately representing the features and topography of an area on a map.

Explanation: The direction of the steepest slope on a contour is at right angles to the contour. Understanding the orientation of slope gradients is crucial in accurately representing the features and topography of an area on a map.

Explanation: When several contours coincide, it indicates a vertical cliff. Understanding the significance of contour coincidences is crucial in accurately representing the features and topography of an area on a map.

Explanation: In the direct method of contouring, the process of locating points lying on a contour is known as vertical control. Understanding the control methods in contouring is crucial in accurately representing the features and topography of an area on a map.

Explanation: The spacing of cross-sections in the indirect method of contouring depends on various factors, including the character of the ground, the scale of the map, and the contour intervals. Understanding these dependencies is crucial in accurately representing the topography of an area on a map.

Explanation: The contour interval for the map at a scale of 1: 25000 is 5 meters in the International System of Units (IS) and 19.70 feet in the Feet-Pound-Second (FPS) system. Understanding the representation of contour intervals in different scales and units is crucial in accurately depicting the topography of an area on a map.

Explanation: Contours are used to determine various aspects, including the intervisibility of points on a contour map, the area of the drainage basin, the capacity of the reservoir, and quantities of earthwork. Understanding the diverse applications of contour lines is crucial in various surveying and mapping activities.

Explanation: Closed contours with higher values inside represent a hill. Understanding the representation of different landforms and terrain features through contour lines is crucial in accurately depicting the topography of an area on a map.

Explanation: The order of accuracy of the elevation of points obtained from a contour map is equal to half of the control interval. Understanding the relationship between the order of accuracy and control intervals is crucial in ensuring the precision and reliability of elevation data derived from contour maps.

Explanation: The best method of interpolation of contours in the direct method of contouring is by computations. Understanding the importance of accurate computations in the contouring process is crucial in ensuring the precise representation of the topography of an area on a map.

Explanation: In a double-line river, contours are stopped at the edge of the river. Understanding the representation of contour lines in the vicinity of rivers is crucial in accurately depicting the features and topography of an area on a map.

Explanation: The boundary of water in a still lake is represented by a contour line. Understanding the depiction of water bodies and their boundaries on a contour map is crucial in accurately representing the features and topography of an area.

Explanation: The location of the contour gradient for a highway is best set out from the saddle down the hill. Understanding the positioning of contour gradients in the context of transportation infrastructure is crucial in ensuring safe and efficient construction and maintenance.

Explanation: For any point on the surface with a given inclination, the possible contour gradient is infinite. Understanding the variability of contour gradients in different terrains is crucial in accurately representing the features and topography of an area on a map.

Explanation: For the route survey of a contour map, the method used is the cross-profile method. Understanding the application of different surveying methods is crucial in accurately representing the features and topography of an area on a map.

Explanation: A contour map of the area is essential before proceeding with the construction of a dam. Understanding the necessity of accurate topographical information in construction planning is crucial in ensuring the safety and stability of the built structure.

Explanation: V-shaped contours represent a valley. Understanding the representation of different landforms through contour lines is crucial in accurately depicting the features and topography of an area on a map.

Explanation: Contour lines of different elevations can unite to form one line only in the case of a vertical cliff. Understanding the representation of different landforms and terrain features through contour lines is crucial in accurately depicting the topography of an area on a map.

Explanation: The curve formed at the junction where the upgrade road meets with the downgrade road is called a summit curve. Understanding the terminology associated with road design and engineering is crucial in accurately representing the features and topography of an area.

Explanation: Contour lines look to cross each other in the case of an overhanging cliff. Understanding the representation of different landforms and terrain features through contour lines is crucial in accurately depicting the topography of an area on a map.

Explanation: The contour line can cross one another on a map only in the case of an overhanging cliff. Understanding the behavior and characteristics of contour lines is crucial in accurately representing the features and topography of an area on a map.

Explanation: Contour lines close somewhere. Understanding the behavior and characteristics of contour lines is crucial in accurately representing the features and topography of an area on a map.

Explanation: The “point of the curve” of a simple circular curve is the point of commencement. Understanding the terminology associated with the layout of circular curves is crucial in the field of transportation engineering and design.

Explanation: The “point of tangency” of a simple circular curve is the point where the curve joins the forward tangent. Understanding the layout and geometry of circular curves is crucial in the field of transportation engineering and design.

Explanation: The central angle subtended by an arc of the curve is given by the formula 1718.9/R, where R is the radius of the curve. This angle is essential in calculating the geometry and layout of the curve.

Explanation: The length of the perpendicular offset from a tangent to the junction of a transition curve and circular curve is equal to 4 times the shift. Understanding this length is crucial in ensuring smooth transitions between different curve segments.

Explanation: With the given radius (R) of 500 m and intersection angle of 120°, the length of the curve is 525m. Calculating the length accurately is crucial for ensuring the proper design and construction of the curved segment.

Explanation: Given the radius of the curve as 50 m and the angle of deflection as 60°, the length of the curve is 52m. Understanding this length is crucial in planning and designing curved segments in various engineering projects.

Explanation: Implementing a transition curve can help avoid the overturning of vehicles on a curve. Understanding the role of transition curves in ensuring smooth and safe transitions is crucial in transportation engineering.

Explanation: A transition curve is introduced between two branches of a compound curve. Understanding the purpose and design considerations for transition curves is crucial in ensuring smooth and safe transitions for vehicles.

Explanation: A transition curve introduced between the tangent and the circular curve should have zero curvature at the junction of the straight and transition curve. This design feature ensures smooth and gradual transitions for vehicles.

Explanation: A compound curve consists of two areas of different radii bending in the same direction and lying on the same side of their common tangent, with their centers on the same side of the curve.

Explanation: Different grades are joined together by a vertical curve. Understanding the use and application of vertical curves is crucial in creating smooth transitions between different grades.

Explanation: Cubic parabola is a type of transition curve. Understanding the characteristics and design features of different types of transition curves is essential in transportation engineering and design.

Explanation: If the length of a transition curve allows the full super elevation to be attained at the junction with the circular curve, the resultant curve is known as a compound curve.

Explanation: The angle subtended by the long chord of a simple curve at its center is equal to the deflection angle. Understanding this angle is crucial in the layout and design of curved segments in transportation engineering.

Explanation: The chord of a curve less than the peg interval is known as the sub chord. Understanding the terminology associated with curved segments is essential for accurate design and construction.

Explanation: The Normal chord of a curve should be greater than the sub chord. Understanding the relationship between these elements is crucial in ensuring the proper design and layout of curved segments.

Explanation: The shape of the vertical curve generally used is parabolic. Understanding the characteristics and design features of different types of vertical curves is essential in transportation engineering.

Explanation: The angle of intersection of a curve is the angle between the back tangent and forward tangent. Understanding this angle is crucial in the layout and design of curved segments in transportation engineering.

Explanation: Given the radius of the curve as 10 m, calculating the length of the curve is essential in planning and designing curved segments in various engineering projects.

Explanation: A boning rod is used in the setting out of sewers. Understanding the equipment and tools used in the construction of various infrastructure elements is crucial for accurate and efficient construction.

Explanation: The instrument used to reproduce plans to a different scale is called a pentagraph. Understanding the tools and instruments used in the field of surveying and mapping is crucial for accurate and detailed work.

Explanation: A planimeter is the instrument used for measuring area on a contour map. Understanding the use and application of different surveying instruments is essential in accurately assessing and representing geographical features.

Explanation: The stadia slide rule is a device used for computing horizontal and vertical distances rapidly and conveniently in surveying. It simplifies distance calculations in the field.

Explanation: A sextant is the instrument used to measure horizontal and vertical angles. It is commonly used for navigation and angle measurement.

Explanation: Direct distance measurement methods are more suitable for measuring distances in plain areas where obstacles and terrain variations are minimal.

Explanation: Electronic Distance Measurement (EDM) typically provides a higher level of accuracy compared to Optical Distance Measurement (ODM) methods.

Explanation: A Distomat is an electromagnetic distance measuring instrument used in surveying to measure distances accurately.

Explanation: A Tellurometer employs radio waves for distance measurement in surveying applications.

Explanation: A Total Station is an electromagnetic distance measurement instrument commonly used in surveying for its integrated capabilities.

Explanation: A Total Station can measure horizontal and slope distances, slopes, differences in level, and coordinates of points, making it a versatile surveying instrument.

Explanation: An altimeter is not typically used in conjunction with a plane table for land surveying.

Explanation: Error arising from the imperfect adjustment of the plate level is classified as instrumental error in surveying.

Explanation: The radius of curvature of the arc of the bubble tube is typically set to 100 meters in surveying instruments.

Explanation: The accuracy of a ‘fix’ obtained through the two-point problem in surveying is often considered not reliable, as it may introduce errors.

Explanation: In the construction of highways or railways, both longitudinal and cross-sectional data are essential for proper design and planning. Longitudinal sections provide information along the route, while cross-sections detail the terrain and features at specific points.