Explanation: The formation of sedimentary rocks occurs through the accumulation and compaction of deposited layers of sand and silt subjected to significant overburden pressures over extended geological timeframes.
Explanation: Igneous rocks form through the solidification of a molten mass of silicates either below or at the surface of the earth, as a result of the cooling and hardening of magma or lava.
Explanation: Metamorphic rocks are formed through the alteration of texture or mineral composition or both of pre-existing igneous or sedimentary rocks, typically due to the influence of high temperature and pressure over time.
Explanation: When molten magma reaches the surface of the earth and solidifies, it leads to the formation of basalts and traps, which are types of igneous rocks.
Explanation: The solidification of molten magma within the earth’s crust results in the formation of granite and pegmatite, both of which are types of igneous rocks.
Explanation: Metamorphism can lead to the transformation of various rock types, such as granite changing into gneiss, sandstone changing into quartzite, and limestone changing into marble.
Explanation: Tripoli is a type of sedimentary rock, typically composed of highly siliceous materials such as diatomaceous earth or opal.
Explanation: Pumice is a type of igneous rock characterized by its frothy and lightweight nature, created from the rapid cooling of lava rich in gas content.
Explanation: Pumice is a type of rock commonly used as a lightweight aggregate due to its porous and lightweight nature, making it suitable for various construction and horticultural applications.
Explanation: Sandstone is a type of sedimentary rock formed from the consolidation of sand and held together by natural cement, often composed of quartz or feldspar.
Explanation: Sandstone primarily consists of grains of quartz, along with varying proportions of other minerals like lime and silica, which contribute to its characteristic composition and texture.
Explanation: Limestone is a type of sedimentary rock primarily composed of calcium carbonate, formed from the accumulation of marine organism remains, such as coral or shells, over millions of years.
Explanation: Slate stone is a type of metamorphic rock that forms from the recrystallization of shale or mudstone, typically under low-grade metamorphic conditions, resulting in its characteristic foliated structure.
Explanation: Diamond is the hardest naturally occurring material, making it the hardest rock among the options provided.
Explanation: Marble is primarily composed of calcium carbonate (lime) and may also contain varying amounts of other minerals like silica, which contribute to its distinctive veined appearance and texture.
Explanation: Granites are a type of silicious rock, composed mainly of feldspar, quartz, and mica, and are widely used as building and decorative stones due to their durability and aesthetic appeal.
Explanation: Calcite is a mineral composed of calcium carbonate, often found in sedimentary rocks, limestone, and metamorphic rocks like marble.
Explanation: Elastomers are elastic polymers that can extend up to ten times their original dimensions, making them highly flexible and ideal for various applications requiring elasticity and resilience.
Explanation: Gravel is a type of sedimentary rock formed from the accumulation of small, rounded fragments of various minerals and rocks, commonly used in construction and landscaping for its durability and drainage properties.
Explanation: Basalt (TBE-GPI) is an extrusive igneous rock, formed from the rapid cooling of lava on the earth’s surface, typically characterized by its fine-grained texture and dark coloration.
Explanation: Gypsum is a soft sulfate mineral and a widely used material in construction. It is a type of sedimentary rock.
Explanation: Conglomerate is a type of sedimentary rock characterized by rounded gravel and pebble-sized clasts cemented together in a matrix.
Explanation: Suitable aggregate is commonly obtained from igneous rock due to its durability and strength, making it an ideal material for construction and road-building purposes.
Explanation: The decrease in the use of stones as building material is attributed to the preference for steel and reinforced concrete (R.C.C.) due to their reduced bulkiness, increased durability, and the challenges associated with the rational analysis of stone strength. Moreover, the convenient availability of stones in plains can be limited, further contributing to the shift away from stone-based construction.
Explanation: Argillaceous rocks primarily consist of clay as their principal constituent, giving them their characteristic properties and appearance.
Explanation: The physical classification of rocks divides them into three main categories: stratified, unstratified, and foliated, based on their respective structural characteristics and formations.
Explanation: The chemical classification of rocks categorizes them into calcareous, argillaceous, and siliceous types, based on their chemical composition and primary constituents.
Explanation: The geological classification of rocks classifies them into three main types: igneous, sedimentary, and metamorphic, based on their respective formation processes and geological origins.
Explanation: Rocks often contain various minerals such as quartz, feldspar, and mica, which contribute to their composition and physical properties.
Explanation: Slate is a metamorphic rock that originates from the transformation of shale under low-grade metamorphic conditions, resulting in its characteristic fine-grained, foliated structure.
Explanation: A rock that exhibits a tendency to split in a definite direction is known as a foliated rock, characterized by its distinct layering and cleavage planes.
Explanation: Quarry sap refers to the moisture content found in freshly quarried stone before it is seasoned or dried. This moisture can impact the stone’s characteristics and properties.
Explanation: Brard’s test is conducted to assess the frost resistance of a stone, which is essential information for evaluating its suitability for outdoor applications, particularly in regions with significant temperature fluctuations.
Explanation: Mica primarily consists of potassium and aluminum silicate, contributing to its characteristic sheet-like structure and various industrial applications.
Explanation: Siliceous rocks are those in which silica serves as the predominant mineral component, influencing their physical and chemical properties.
Explanation: Calcareous rocks are those primarily composed of calcium carbonate, which is derived from marine organisms and sedimentation processes over time.
Explanation: Kaolin, commonly known as china clay, is an argillaceous rock that is rich in kaolinite, a clay mineral used in various industrial applications, including ceramics, paper, and cosmetics.
Explanation: Trap is an igneous rock often used in construction, known for its durability and strength, making it suitable for various building and road construction purposes.
Explanation: Marble typically has a minimum hardness number of around 3 on the Mohs scale, which measures the relative hardness of minerals, making it relatively softer compared to other stones like granite or quartzite.
Explanation: Granite primarily consists of a combination of quartz and feldspar, which contributes to its characteristic speckled appearance and durability, making it a popular choice for countertops and building facades.
Explanation: Common sand is primarily composed of quartz, a hard, durable mineral commonly found in the Earth’s crust and used in various construction and industrial applications.
Explanation: Shingle refers to small, rounded stones often found on beaches or in riverbeds and is typically made up of decomposed laterite material.
Explanation: Cleavage refers to the tendency of minerals to split along specific planes, producing smooth, flat surfaces, and is a significant characteristic used to identify and classify minerals.
Explanation: Granite exhibits a high hardness coefficient, making it exceptionally durable and suitable for various construction applications, including countertops and flooring.
Explanation: Silica does not display good cleavage, as it tends to fracture rather than split along specific planes due to its rigid and amorphous structure.
Explanation: A high-quality stone should ideally absorb water at a rate less than 5%, ensuring its durability and resistance to weathering and moisture-related damage.
Explanation: Talc is the softest rock among the options provided, known for its characteristic greasy or soapy feel and its widespread use in various industrial applications, including cosmetics and pharmaceuticals.
Explanation: Stones with water absorption exceeding 10% are typically rejected as they may be prone to damage from freezing, thawing, or other weather-related effects, leading to potential structural issues in construction applications.
Explanation: Good quality building stones should ideally not contain any soluble salts, as their presence can lead to deterioration and structural damage over time, compromising the integrity of the construction.
Explanation: Building stones can be dressed very easily soon after quarrying, as they are softer and more malleable at this stage, allowing for smoother cutting and shaping processes during construction and masonry work.
Explanation: Dressing of stone refers to the process of preparing the stone surface to achieve uniformity and desired shape and size, essential for various construction and masonry purposes.
Explanation: Quarrying is the process of extracting stones of different sizes and shapes from natural rock formations, essential for sourcing raw materials for construction and architectural purposes.
Explanation: Jumper and crowbar are commonly used tools in the quarrying of stones, aiding in the extraction and splitting of large rocks into smaller, manageable pieces for various construction and building projects.
Explanation: Gunpowder is not typically used for blasting rocks underwater, as it may not be as effective as other explosives due to its specific properties and limitations in aquatic environments.
Explanation: Marble can be found in the Bagmati region, known for its extensive deposits of high-quality marble used in various construction and decorative applications.
Explanation: In stone masonry, stones are often positioned so that their natural bedding planes are perpendicular to the direction of pressure they carry, ensuring maximum stability and load-bearing capacity within the structure.
Explanation: When molten magma intrudes into preexisting rock layers within the Earth’s crust and cools and solidifies, it forms an intrusive rock, also known as a plutonic rock, characterized by its crystalline structure and slow cooling process.
Explanation: Pegmatite is a coarse-grained, intrusive igneous rock known for its large crystal sizes, typically found in dikes and veins within other rocks, often containing valuable minerals and gemstones.
Explanation: Limestone is a sedimentary rock formed from the accumulation of marine life remains and is categorized as an aqueous, stratified, and sedimentary rock due to its origin and distinct layered structure.
Explanation: Laterite is an example of an agrillaceous rock, rich in iron and aluminum, commonly found in tropical regions, often used as a building material due to its durability and availability in certain geographical areas.
Explanation: Both slate and marble belong to the category of metamorphic rocks, characterized by their formation through the transformation of preexisting rock types under intense heat and pressure, resulting in distinct changes in their mineralogy and texture.
Explanation: Sandstone belongs to the category of sedimentary rocks, formed from the accumulation and cementation of sand grains over time, often used in construction and architectural projects due to its durability and versatility.
Explanation: In arch construction, stratified stones are typically positioned so that their planes are radial, allowing for optimal load distribution and stability within the arch structure.
Explanation: Stones used for carving ornamental and architectural features should ideally be soft, allowing for intricate and detailed carving work to create decorative and aesthetically pleasing designs.
Explanation: Heavy stones are more suitable for gravity retaining walls, providing the necessary stability and resistance to earth pressure, ensuring the structural integrity and durability of the wall over time.
Explanation: Basalt and trap granite are commonly used for railway ballast due to their durability, resistance to wear and tear, and ability to withstand the dynamic loads and impacts associated with railway transportation.
Explanation: Statuary marble used for sculpting work is primarily white, known for its smooth texture, fine grain, and ability to retain intricate details and designs, making it a popular choice for sculptures and artistic creations.
Explanation: Granite is commonly used for bridge piers and columns due to its high strength, durability, and resistance to weathering and erosion, ensuring the structural integrity and longevity of the bridge.
Explanation: The crushing strength of a stone is influenced by its texture and specific gravity, determining its ability to withstand compressive forces without undergoing deformation or structural failure.
Explanation: Most building stones should ideally have a crushing strength of more than 1000 kg/cm² to ensure their suitability for construction purposes and to withstand the applied loads and pressures.
Explanation: The specific gravity for most ordinary building stones typically ranges between 2.4 to 3.0, indicating their density and relative heaviness compared to water, which is essential for assessing their structural suitability and durability.
Explanation: Granite, although durable and fire-resistant, is not always considered suitable for ordinary building purposes due to its higher cost compared to other building materials, making it less economically viable for common construction projects.
Explanation: The attrition test on stone is performed to determine the rate of wear, evaluating the stone’s resistance to abrasion and its ability to withstand deterioration over time, especially in high-traffic areas and harsh environmental conditions.
Explanation: A good building stone should possess various attributes, including good appearance and color, resistance to fire, as well as sufficient hardness and toughness, ensuring its suitability for construction purposes and longevity.
Explanation: Sandstone typically exhibits a granular texture, characterized by the presence of individual sand grains cemented together, resulting in a coarse, rough texture often used in various construction and decorative applications.
Explanation: Asbestos has a fibrous fracture, resulting from its unique mineral structure composed of thin, elongated fibers, making it suitable for various industrial applications due to its strength, heat resistance, and insulating properties.
Explanation: Among the options provided, granite exhibits the highest compressive strength, making it a popular choice for various construction and structural applications due to its ability to withstand substantial loads and pressures without deformation.
Explanation: Plutonic rocks are formed due to the slow cooling of magma at significant depths beneath the Earth’s surface, resulting in the formation of large crystals and a coarse-grained texture, distinguishing them from volcanic rocks.
Explanation: Among the options provided, gneiss generally exhibits the highest crushing strength, making it suitable for various construction applications requiring materials with high load-bearing capacity and durability.
Explanation: Among the options provided, laterite generally exhibits the lowest crushing strength, making it less suitable for applications requiring materials with high load-bearing capacity and structural integrity.
Explanation: Marble powder is not typically used in the process of quarrying, unlike the other options listed, which are commonly employed for various tasks related to the extraction, fragmentation, and processing of stones and minerals in the quarrying industry.
Explanation: Quartzite is classified as a metamorphic rock, formed from the metamorphosis of sandstone under high pressure and heat, resulting in the recrystallization of its mineral structure and the formation of a durable and resistant rock material.
Explanation: Basalt is categorized as an extrusive igneous rock, formed from the rapid cooling of lava on the Earth’s surface, resulting in its fine-grained texture and characteristic dark color, commonly found in volcanic regions.
Explanation: Granite can exhibit various colors, including brown, green, and grey or pink, depending on the specific mineral composition and impurities present in its structure, contributing to its aesthetic diversity and versatility in architectural and design applications.
Explanation: Compact sandstone generally exhibits better fire-resisting characteristics compared to the other options listed, due to its dense and closely packed structure, providing enhanced resistance to heat and fire-related damage in various construction and masonry applications.
Explanation: Quartzite is known for its exceptional weather-resisting properties, making it highly durable and resistant to environmental factors such as weathering, erosion, and chemical deterioration, contributing to its widespread use in various construction and architectural projects.
Explanation: Quartz is the primary constituent responsible for the strength and durability of granite, contributing to its high compressive strength, abrasion resistance, and overall robustness, making it a popular choice for various construction and structural applications.
Explanation: A spalling hammer is commonly used for the rough dressing of stones, facilitating the process of shaping and refining the surface of stones to achieve the desired texture, shape, and appearance, essential for various construction and masonry applications.
Explanation: A jumper is a specialized tool used in the quarrying of stones, aiding in the extraction and splitting of large rocks and boulders from natural rock formations, essential for sourcing raw materials for construction and masonry purposes.
Explanation: The compressive strength of stone is typically determined through a crushing test, evaluating the stone’s ability to withstand compressive forces without undergoing deformation or structural failure, essential for assessing its suitability for various construction and architectural applications.
Explanation: The Smith test is conducted on stones to assess their resistance to soluble and clayey water, evaluating their durability and stability when exposed to various types of water, ensuring their suitability for construction in different environmental conditions and locations.
Explanation: Terrazzo is an artificial stone made from pieces of marble and cement, commonly used for floor facing of walls and various decorative applications, known for its durability and aesthetic appeal in architectural and interior design projects.
Explanation: A heavy stone is most suitable for retaining walls, providing the necessary stability and resistance to earth pressure, ensuring the structural integrity and longevity of the wall over time, particularly in challenging environmental conditions and terrain.
Explanation: Limestone is indeed a sedimentary rock, typically formed from the accumulation of organic remains and sediments over time, reflecting its specific origin and geological characteristics in the context of rock classification.
Explanation: A stone suitable for rubble masonry should ideally be hard, ensuring its ability to withstand external forces and environmental factors without undergoing damage or deterioration, contributing to the stability and longevity of the masonry structure.
Explanation: The weight test is an important assessment conducted on stones used in docks and harbors to evaluate their density and mass, ensuring their stability and resistance to the dynamic and harsh marine environment, essential for the durability and longevity of the structures.
Explanation: Clay is a good fire-resistant material known for its ability to withstand high temperatures and heat exposure without undergoing significant damage or structural compromise, making it a suitable choice for various fireproof applications in construction and manufacturing.
Explanation: During the production of cement, raw materials are typically mixed in a ball mill, allowing for the grinding and blending of various components to form a homogeneous mixture and achieve the desired chemical composition and physical properties required for cement manufacturing.
Explanation: The main constituent of cement, in descending order, typically includes lime, silica, alumina, iron oxide, and magnesia, each playing a crucial role in the chemical composition and overall properties of the final cement product used in various construction and building applications.
Explanation: The loss of ignition in cement should ideally not exceed 4%, reflecting the permissible limit of weight loss during the ignition process, indicating the presence of volatile compounds and organic materials that may impact the quality and performance of the final cement product.
Explanation: The amount of insoluble residue and residual retained on the IS90 sieve for Ordinary Portland Cement (OPC) typically ranges around 1.5% and 10%, respectively, reflecting the permissible levels of impurities and residue content in the cement, ensuring its quality and adherence to standard specifications and requirements.
Explanation: All the options are correct. Normally, concreting is done above 20°C, the optimum temperature for concreting is 27°±2°, and the consistency test is indeed done at a temperature of 25°C to 29°C.
Explanation: Gypsum is added to cement to slow down the fast reacting property of tricalcium aluminate, which helps in controlling the setting time of cement and prevents the development of early strength.
Explanation: Limestone is the most commonly used raw material in the manufacture of cement. It is a crucial component that provides the necessary calcium for the chemical reactions that occur during the production of cement.
Explanation: All the options are true. A good quality cement typically has a gray color, feels cool to the touch when thrusting one’s hand in the cement bag, and is smooth when rubbed between fingers.
Explanation: The strength of cement typically remains at 100% up to three months, reflecting its ability to maintain its compressive strength without any significant reduction during this initial period after curing.
Explanation: The strength of cement may reduce by approximately 30% after six months, indicating a gradual decline in its compressive strength over an extended period after the initial curing phase.
Explanation: Water absorption of cement should ideally not be more than 5%, ensuring its resistance to moisture and water penetration, which can otherwise lead to degradation and loss of strength over time.
Explanation: The initial setting of cement is primarily caused by the formation of tricalcium aluminate, which triggers the process of hydration, leading to the initial development of strength and the setting of the cement paste.
Explanation: Cement typically contains the maximum percentage of lime (calcium oxide) among the options listed. Lime is a key ingredient that contributes to the hydration process and the binding properties of cement paste.
Explanation: As per IS specification, the minimum time for the initial setting of ordinary Portland cement is 30 minutes, indicating the standard duration for the cement to attain its initial rigidity after the addition of water.
Explanation: As per IS specification, the maximum final setting time for ordinary Portland cement is 10 hours, reflecting the defined duration for the completion of the setting process and the attainment of its final strength and rigidity after the addition of water.
Explanation: Undesirable properties of cement are often attributed to the formation of tricalcium aluminate, which can lead to the development of certain characteristics that might impact the performance and quality of the cement in various construction applications.
Explanation: The setting and hardening of cement after the addition of water primarily occur due to the hydration and hydrolysis of some constituent compounds of cement, which act as a glue, facilitating the bonding of cement particles and the development of strength and rigidity over time.
Explanation: A type of cement is considered good if it contains a large amount of C3S (tricalcium silicate), as this compound contributes significantly to the development of early strength and the overall strength characteristics of the cement.
Explanation: The constituents of cement that act as binders are typically dicalcium silicate and tricalcium silicate, as these compounds play a crucial role in the binding and cementing process that occurs during the hydration and setting of cement paste.
Explanation: A slow-setting cement often has a higher percentage of dicalcium silicate, which contributes to its delayed setting time and allows for more extended workability and placement time during construction activities.
Explanation: Alite, belite, and celite are the normally bogus compounds found in cement during the burning process. These compounds can impact the quality and properties of the cement, affecting its performance in different applications.
Explanation: When water is added to cement, the cement hydrates, and chemical reactions take place while cement is setting, resulting in an increase in temperature and the generation of a significant quantity of heat. This phenomenon is known as the hydration of cement.
Explanation: The dormant period (2-5hr) is primarily concerned with the hydration of cement, which is the chemical reaction between cement and water leading to the development of strength and rigidity in the cement paste.
Explanation: Flash setting of cement refers to the stiffening of cement without any significant strength development. It is characterized by the rapid stiffening of the cement paste, which can hinder the workability and placement of the cement during construction activities.
Explanation: The strength of Rapid Hardening Portland Cement (RHPC) for one day is generally equivalent to the strength of Ordinary Portland Cement (OPC) for three days. RHPC is known for its early strength development, making it a suitable option for projects that require rapid setting and early load-bearing capacity.
Explanation: An excess quantity of CaCl2 (>2%) and triethanolamine (>0.06%) admixtures behave like a retarder, as they slow down the setting time of cement, providing extended workability and placement time during construction activities.
Explanation: The possibility of bleeding, segregation, and laitance is reduced by the use of air-entraining agents, which create small air bubbles in the concrete, enhancing its workability and resistance to segregation and bleeding during the construction process.
Explanation: Workability is tested by various methods, including the slump test, vee bee test, and compacting factor (C.F.) test, among others. These tests help evaluate the consistency and flow characteristics of the concrete, providing insights into its workability during placement and compaction.
Explanation: The air-entraining agents in concrete are additives that introduce and stabilize microscopic air bubbles in the concrete, enhancing its workability and durability. Common sources of air-entraining agents include animal fats, natural wood resins, and alkali salts, all of which contribute to the improved properties of the concrete.
Explanation: Among the options listed, calcium chloride is the most commonly used accelerator for concreting. It accelerates the setting time of concrete, enabling faster strength development, which is particularly useful in colder temperatures or when a rapid setting is required for construction projects.
Explanation: The workability of concrete is enhanced when there is an excess of cement, water, or round aggregate. These factors contribute to the overall consistency and ease of handling during the concrete placement and finishing processes, ensuring that the concrete remains easy to use and manipulate.
Explanation: Portland pozzolana cement typically contains 20 to 30% of pozzolana, a finely ground material that is used as a partial substitute for Portland cement. This addition enhances the workability and durability of the cement while reducing the amount of cement needed, making it an environmentally friendly choice.
Explanation: All of the statements are correct. Portland pozzolana cement (PPC) generally gains strength at a slower rate than ordinary Portland cement (OPC), but its ultimate strength is often higher. Additionally, PPC exhibits a higher resistance to chemical attacks, making it a popular choice for various construction applications.
Explanation: Quick-setting cement often contains aluminium sulphate as an additive. This compound accelerates the setting time of the cement, enabling faster strength development, which is particularly beneficial when rapid setting is required for construction projects, such as in underwater structures.
Explanation: In low heat cement, the constituent that is kept to a minimum is tricalcium aluminate. This is done to reduce the heat of hydration during the setting process, preventing potential cracking or damage due to the high heat generated by the cement.
Explanation: The raw materials that have more than a 10% proportion in the manufacture of cement are calcium oxide and silica. These materials are essential components in the production of cement, contributing to its overall strength and durability.
Explanation: Tri-calcium silicate is considered the best cementing material in cement. It is responsible for the initial setting and hardening of cement, providing the necessary adhesive properties that contribute to the strength and durability of the final concrete product.
Explanation: The freshness of cement is determined by several factors, including its lack of lumps, its smooth consistency when rubbed between fingers and thumb, and the cool feeling it gives when the hand is inserted in the bag. These characteristics ensure that the cement is in optimal condition for use in construction projects.
Explanation: The consistency test for cement is typically conducted within the temperature range of 25°C to 29°C. This specific temperature range ensures that the test accurately reflects the consistency of the cement, allowing for precise measurements and reliable results.
Explanation: The consistency test for cement is primarily performed to determine the correct water-cement ratio. This ratio is crucial in ensuring the optimal workability and strength of the cement, allowing for efficient and effective use in various construction applications.
Explanation: In the Vicat apparatus test, for normal consistency, the penetration should typically be between 30 to 35 mm. This range indicates the appropriate water content required to achieve the desired consistency of the cement, ensuring optimal workability during the construction process.
Explanation: Le-Chatelier’s apparatus is primarily used to conduct the soundness test of cement. This test assesses the potential volume change of the cement due to the presence of uncombined lime, which can lead to disruptive and damaging effects, particularly in large structures or under certain environmental conditions.
Explanation: The soundness test of cement primarily determines the quantity of free lime present in the cement. Free lime can have detrimental effects on the performance and durability of cement, leading to potential cracks or damage in the structure over time.
Explanation: In the briquette test, the minimum acceptable seven-day tensile strength of good Portland cement should not be less than 25 kg/cm^2. This ensures the cement’s durability and reliability, indicating its suitability for various construction applications.
Explanation: The seven-day compressive strength of good Portland cement, as determined from the compressive test on cement-sand mortar cubes, should not be less than 175 kg/cm^2. This strength requirement ensures the stability and structural integrity of the cement, making it suitable for various construction projects.
Explanation: The presence of excessive free lime and magnesia in the cement can render the cement unsound, leading to potential cracking or disruption in the structure over time. It is crucial to control the proportion of these components to ensure the overall quality and durability of the cement.
Explanation: The dry process of manufacturing cement has become obsolete primarily because it is slow and costly, results in the production of inferior quality cement, and is challenging to maintain the correct proportions of the constituents. These factors have contributed to the prevalence of the wet process, which is more efficient and effective in producing high-quality cement.
Explanation: Rapid hardening cement achieves early strength primarily due to a larger proportion of lime that is ground finer than in ordinary cement. This characteristic enables the rapid hardening of the cement, ensuring quick strength development and setting, which is beneficial for time-sensitive construction projects.
Explanation: Portland cement manufactured from pure white chalk and clay without any iron oxide content is commonly referred to as white cement. It is primarily used in architectural applications where aesthetic appeal and color consistency are crucial, ensuring a visually appealing and high-quality finish.
Explanation: Tri-calcium aluminate is the constituent of the cement that sets and hardens first upon the addition of water. This property is essential for the initial setting process of the cement, contributing to its adhesive and structural properties, ensuring its stability and durability over time.
Explanation: The moisture content of cement is a critical factor in determining its effectiveness and durability. If the absorbed moisture content of cement exceeds 5%, it can render the cement useless, leading to potential degradation, reduced strength, and compromised performance, particularly in construction applications.
Explanation: In the sieve analysis of the fineness test, the residue on the IS sieve No. 90μ after 15 minutes of sieving should not exceed 10%. This ensures that the cement is finely ground and does not contain excessive coarse particles, ensuring its optimal performance and consistency in various construction applications.
Explanation: Quick setting cement is particularly useful for construction projects involving structures that need to be set quickly, especially in underwater applications where rapid hardening is crucial.
Explanation: The initial and final setting times of ordinary Portland cement are typically 30 minutes and 10 hours, respectively, which are crucial time frames in construction operations.
Explanation: Quick setting cement has considerably shorter initial and final setting times, making it a preferred choice for projects requiring rapid completion and early strength development.
Explanation: Expansive cement is often employed for patching pavement works, primarily due to its ability to counteract the potential cracking and damage caused by temperature fluctuations and seasonal changes.
Explanation: Pozzolana Portland cement generally takes more time than ordinary Portland cement to gain strength, often necessitating careful planning and scheduling during construction activities.
Explanation: Pozzolana Portland cement typically exhibits higher ultimate strength compared to ordinary Portland cement, making it a favorable option for projects where enhanced strength characteristics are desired.
Explanation: The ultimate strength of cement is primarily provided by dicalcium silicate, an essential constituent that contributes significantly to the overall strength development of the cement matrix.
Explanation: In the test for loss on ignition, the cement is subjected to a temperature of 1000°C to determine the precise amount of combustible substances present in it.
Explanation: Loss on ignition in cement should ideally be limited to 4% to ensure the absence of excessive combustible materials that might compromise the overall quality and performance of the cement.
Explanation: The presence of insoluble residues in good cement should be less than 1.5%, indicating the purity and high quality of the cement composition.
Explanation: The volume of one bag of cement weighing 50 kg is typically 0.0347 cubic meters, which is a crucial factor to consider during transportation and storage.
Explanation: Slag cement usually contains a significant amount of sulphate, contributing to its unique properties and performance characteristics, especially in terms of durability and strength.
Explanation: For the determination of the initial setting time, the water to be added is 0.85 times the percentage of water required for normal consistency (P).
Explanation: Poorly mixed cement concrete often leads to the formation of honeycombs, resulting in compromised structural integrity and durability of the concrete.
Explanation: The strength of cement generally decreases with prolonged storage, emphasizing the importance of using fresh cement for ensuring optimal performance and durability of concrete structures.
Explanation: Cement should ideally be stored on a dry platform to prevent the absorption of moisture, which can adversely affect its quality and performance in concrete.
Explanation: The fineness of cement is primarily determined by the air permeability method, which measures the specific surface area of the cement particles.
Explanation: Sand reaches its minimum volume when it is in either an absolutely dry state or an absolutely wet state, highlighting the importance of considering its moisture content during construction.
Explanation: The main constituents of Portland cement include lime, silica, and alumina, which play crucial roles in the overall properties and behavior of the cement.
Explanation: Portland cement is the most commonly used type of cement in general construction due to its versatile properties and widespread availability.
Explanation: The chemical reaction between cement and water, resulting in the formation of a solid matrix, is known as hydration, which is a fundamental process in concrete formation and hardening.
Explanation: Gypsum is the most commonly used retarder in cement, helping to regulate the setting time of the concrete to ensure workability and proper placement during construction.
Explanation: Clay soil, which typically contains silica and alumina, is considered ideal for making bricks due to its plasticity and binding properties when mixed with water.
Explanation: Alkali and kankar are both impurities that are not desirable in soil used for brick formation as they can significantly affect the quality and structural integrity of the resulting bricks.
Explanation: Low porosity in bricks typically indicates high strength, which is a desirable characteristic for ensuring the durability and long-term performance of the brick structures.
Explanation: Silica is the key ingredient in brick earth that enables the brick to retain its shape during the firing process, contributing to the overall strength and stability of the brick.
Explanation: Good brick earth typically contains a percentage of silica ranging between 50% and 60%, contributing to the favorable properties and characteristics of the resulting bricks.
Explanation: The red color of the brick is primarily due to the presence of iron oxide, which gives the brick its characteristic reddish appearance.
Explanation: As per the Nepal Standard (NBC205:2013), the standard size of a brick is 230x115x57 mm³, which is an essential specification for ensuring uniformity and compatibility in construction projects.
Explanation: During the testing of compressive strength, the load is typically applied at the rate of 14 N/mm² per minute to evaluate the structural integrity and load-bearing capacity of the bricks.
Explanation: Good brick earth generally contains a percentage of alumina ranging between 20% and 30%, contributing to the overall plasticity and workability of the brick material during the manufacturing process.
Explanation: Excess silica in brick earth can lead to brittleness, which can compromise the structural integrity and overall performance of the bricks, making them more prone to breakage and damage.
Explanation: Excess alumina in brick earth can lead to cracking and warping during the drying process, affecting the overall shape and structural stability of the bricks, leading to potential defects and performance issues.
Explanation: Alumina in brick earth primarily serves the function of imparting plasticity, making it easier to shape and mold the bricks during the manufacturing process.
Explanation: The process of kneading clay, water, and other ingredients to make a brick is referred to as tempering, which is a crucial step in ensuring the proper consistency and workability of the brick material before molding.
Explanation: The process of mixing sand with the powdered natural soil to enhance the quality and properties of the resulting bricks is commonly known as blending, an important step in achieving the desired characteristics and performance of the bricks.
Explanation: Excessive iron oxide in brick earth can lead to a color change, causing the brick color to shift from red to dark blue, which can impact the overall aesthetic appeal and market value of the bricks.
Explanation: Lime is mixed with brick earth to help prevent shrinkage, ensuring that the bricks maintain their shape and structural integrity during the drying and firing process, minimizing potential defects and deformities.
Explanation: The maximum percentage of water absorption of 1st class bricks in 24 hours should be limited to 15% to ensure that the bricks maintain their structural stability and durability when exposed to moisture.
Explanation: The maximum percentage of water absorption of 2nd class bricks in 24 hours should be limited to 20% to maintain their overall structural integrity and prevent potential damage or degradation caused by excessive moisture absorption.
Explanation: The crushing strength of 1st class bricks should not be less than 105 kg/cm², ensuring that they can withstand the applied load and pressure without undergoing deformation or failure, demonstrating their high load-bearing capacity and durability.
Explanation: The minimum compressive strength of 2nd class bricks should be 70 kg/cm², ensuring that they possess sufficient strength to withstand the expected loads and pressures experienced in construction projects.
Explanation: Bricks are typically burnt at temperatures ranging from 700°C to 1000°C when low melting clay is used, ensuring proper vitrification and structural integrity of the bricks during the firing process.
Explanation: During the burning of dried bricks, the sequence of chemical changes that occur involves dehydration, followed by oxidation and vitrification, ensuring the proper fusion of the clay particles and the formation of a durable and strong brick structure.
Explanation: For burning clay products like sewer pipes, the necessary chemical change that occurs is vitrification, where the clay particles are fused together to form a dense and impermeable structure, ensuring the required strength and durability for the intended application.
Explanation: As per the NS (Nepal Standard), for one cubic meter of brick masonry, the number of machine-made bricks required is 530, providing a standard guideline for the efficient and accurate estimation of material quantities in construction projects.
Explanation: According to the IS (Indian Standard) standard, the number of standard bricks required for one cubic meter of brick masonry is 500, serving as a key reference for ensuring the proper calculation and utilization of bricks in construction activities.
Explanation: The red color obtained by the bricks is primarily due to the presence of iron oxide, which imparts the characteristic reddish hue to the bricks, making them visually appealing and widely used in various construction applications.
Explanation: The soil used for the manufacture of bricks should preferably not contain pebbles, as their presence can negatively impact the structural integrity and overall quality of the bricks, leading to potential defects and performance issues.
Explanation: Tiles are commonly used for covering roofs and flooring as well as for making drains, serving as versatile construction materials that offer durability, aesthetic appeal, and effective water management solutions.
Explanation: As per the NS (Nepal Standard) norms, the amount of local brick required for one cubic meter of masonry is 560, providing a standardized measure for estimating material quantities and ensuring accurate calculations in construction projects.
Explanation: The internal size of the mould used in brick preparation is typically larger than the size of the fully burnt brick, allowing for the appropriate shrinkage and expansion of the brick material during the firing process, ensuring the desired dimensions and quality of the final product.
Explanation: The nominal size of a modular brick is typically greater than the actual brick size, accounting for the necessary joint thickness and ensuring accurate measurements and specifications in construction activities.
Explanation: If fine sand or ash is sprinkled on the inner surface of the mould during the brick-making process, the resulting bricks are known as sand moulded, indicating the method used for shaping and preparing the bricks before firing.
Explanation: A pug mill is primarily used for the preparation of clay, ensuring the proper mixing and homogenization of clay with other additives or materials to achieve the desired consistency and properties required for the brick-making process.
Explanation: One of the advantages of clamp burning compared to kiln burning is that it involves less initial cost, making it a cost-effective option for brick production, particularly for smaller-scale operations or projects with limited budget constraints.
Explanation: The over ground continuous kiln is commonly referred to as Hoffman’s kiln, representing a type of continuous kiln used for the firing and production of bricks on a large scale, providing an efficient and continuous operation for brick manufacturing.
Explanation: The kiln that can work regularly throughout the year is referred to as Hoffman’s kiln, known for its continuous and consistent operation, making it suitable for large-scale brick production and meeting the demand for bricks in various construction projects.
Explanation: The shape of Hoffman’s continuous kiln is generally circular, enabling the efficient and uniform distribution of heat during the brick firing process, ensuring consistent quality and structural integrity in the produced bricks.
Explanation: Fire bricks should be laid in fire clay mortar, providing the necessary adhesion and support for the bricks, ensuring their proper arrangement and stability in high-temperature applications or environments where heat resistance is essential.
Explanation: Fire bricks are primarily used to decrease heat flow, serving as effective insulating materials that can withstand high temperatures while minimizing heat transfer, making them suitable for various industrial and construction applications where thermal resistance is required.
Explanation: Fire clay consists of hydrated aluminium silicate, which is a key component responsible for the heat-resistant and refractory properties exhibited by fire clay, making it suitable for various high-temperature applications such as in the production of fire bricks and other ceramic materials.
Explanation: Frog refers to the depression on the top face of a brick, which is designed to facilitate the proper adhesion of mortar during bricklaying, ensuring secure and stable placement within the masonry structure.
Explanation: Porcelain is commonly used as sanitary wares, including products such as sinks, toilets, and other bathroom fixtures, owing to its durability, water resistance, and aesthetic appeal, making it an ideal material for sanitary applications.
Explanation: The function of the frog in a brick includes forming a key during laying, reducing the weight of the brick, and sometimes serving as a means of advertising the manufacturer, depending on the design and branding preferences adopted by the brick-making company.
Explanation: In brick masonry, the frog of the brick is typically kept on the top face, ensuring that the mortar fills the depression in the brick and providing enhanced bonding and stability within the masonry structure.
Explanation: In brick laying, the tool used for lifting and spreading mortar and for forming joints is a trowel, which is a flat-bladed tool with a handle, essential for the precise application and shaping of mortar during bricklaying tasks.
Explanation: Bull nose bricks are typically not used in arches, as their rounded shape and design are more suited for applications such as walls and the rounding off of sharp corners, providing a smooth and decorative finish in various construction projects.
Explanation: Hollow bricks are commonly used for thermal insulation purposes, providing effective heat regulation and energy efficiency in buildings, making them an ideal choice for construction projects that require optimal temperature control and energy conservation measures.
Explanation: The broken portion of a brick is referred to as a bat, which can be reused or repurposed for various construction tasks, serving as a cost-effective and sustainable solution for minimizing material waste in construction projects.
Explanation: Terracotta is commonly used in building for ornamental work, contributing to the aesthetic appeal and artistic expression in architectural designs, particularly in the creation of decorative facades, sculptures, and other artistic elements in buildings.
Explanation: Bloating of bricks is primarily due to the presence of excess carbonaceous matter and sulphur, leading to the formation of gases during the firing process, resulting in the expansion and bloating of the bricks, which can compromise their structural integrity and quality.
Explanation: Swelling of bricks is known as bloating, which refers to the expansion and distortion of the bricks caused by the presence of excess carbonaceous matter and sulphur, leading to the formation of gases that result in the bloating effect.
Explanation: The quantity of sand in bricks is approximately about 3/5th of the brick’s volume, contributing to the overall composition and properties of the bricks, including their density, strength, and durability in various construction applications.
Explanation: Bricks are properly soaked in water before use to avoid the chances of absorption of water from the mortar, ensuring that the bricks do not absorb excessive moisture from the mortar, which can potentially compromise the strength and stability of the masonry structure.
Explanation: In one day, the height of brick masonry construction should generally not exceed 3m, ensuring that the construction process proceeds at a manageable pace, allowing for proper curing and bonding of the mortar between the bricks, thereby maintaining the structural integrity and stability of the building under construction.
Explanation: For the manufacture of bricks, the topsoil is typically removed to a depth of 20cm, ensuring the extraction of suitable clay material for the brick-making process, enabling the production of high-quality and durable bricks that meet the required standards and specifications in construction activities.
Explanation: Tampering of soil for the manufacture of bricks can be done using various methods, including feet, pug mill, or the feet of cattle, ensuring the proper mixing and preparation of the clay material, achieving the desired consistency and properties required for the production of high-quality bricks.
Explanation: In the case of a clamp for the burning of bricks, the bricks/fuel are typically laid at a slope of 15°, facilitating the efficient and uniform firing of the bricks, ensuring the proper distribution of heat and combustion throughout the clamp, resulting in well-burnt and durable bricks.
Explanation: Normally, the bricks (1st class) obtained from pazawah are about 60%, reflecting the quality and standard of the bricks produced through the traditional clamp burning process, which is commonly used for the firing and production of bricks in various construction projects.
Explanation: The top and sides of a clamp (pazawah) are plastered with mud and cow dung to prevent the escape of heat, ensuring that the heat generated during the firing process remains within the clamp, allowing for the effective and uniform firing of the bricks, while also minimizing energy loss and ensuring efficient fuel consumption.
Explanation: Lamination of bricks occurs due to the presence of entrapped air in the voids of the clay, leading to the formation of layers or laminations within the bricks, which can weaken their structural integrity and compromise their quality and durability in various construction applications.
Explanation: Strike is used to remove the surplus clay of the mould during the brick-making process, ensuring the proper shaping and formation of the bricks, resulting in uniform and well-defined dimensions and surfaces that meet the required standards and specifications in construction activities.
Explanation: Refractory bricks can be classified into various types, including neutral refractory bricks, acid refractory bricks, and basic refractory bricks, each designed to withstand specific temperature ranges and chemical environments, making them suitable for use in various high-temperature applications such as furnace linings and combustion chambers.
Explanation: Chromite bricks belong to the category of neutral refractory bricks, known for their excellent heat resistance and durability in high-temperature environments, making them suitable for use in various industrial applications that involve exposure to extreme heat and chemical conditions.
Explanation: Bauxite bricks belong to the category of basic refractory bricks, characterized by their high alumina content and excellent resistance to alkaline substances, making them suitable for use in applications involving exposure to high temperatures and strong chemical reactions, such as in the construction of furnaces and kilns.
Explanation: The types of bricks used for the lining of the furnace/combustion chamber are refractory bricks, specifically designed to withstand high temperatures and harsh chemical environments, ensuring the efficient and reliable operation of furnaces and combustion chambers in various industrial processes.
Explanation: Refractory bricks are specially manufactured to withstand high temperatures, making them suitable for use in applications involving extreme heat exposure, such as in the construction of furnace linings, kilns, and other high-temperature industrial processes, ensuring their durability and long-term performance under challenging operating conditions.
Explanation: Second-class bricks are characterized by their ability to produce a metallic sound when struck, indicating their relatively lower quality and strength compared to first-class bricks, often used in non-structural and non-load-bearing applications in construction projects, where their strength requirements are less stringent.
Explanation: Wooden molds for brick-making are generally made from shisham wood, known for its durability, water resistance, and resistance to fungal attacks, making it suitable for use in the construction of durable and long-lasting wooden molds used in the brick-making process.
Explanation: In the case of refractory bricks, the percentage of alumina is typically increased, ensuring their enhanced heat resistance and chemical stability, making them suitable for use in high-temperature environments and industrial applications that involve exposure to extreme heat and harsh chemical conditions.
Explanation: A pug mill is used for tempering brick earth, ensuring the proper mixing and conditioning of the clay material, achieving the desired consistency and properties required for the production of high-quality bricks in various construction projects, ensuring their strength and durability.
Explanation: If rainwater falls on hot bricks, resulting in the deformation of the brick’s shape, the defect is known as chuffs, highlighting the susceptibility of bricks to deformation and structural damage when exposed to sudden changes in temperature and moisture conditions during the production and curing processes.
Explanation: The discoloration and formation of white deposits on the surface of bricks due to the presence of a relatively large proportion of soluble salts is known as efflorescence, representing a common issue that can affect the appearance and structural integrity of bricks, requiring appropriate preventive measures and treatment during the production and curing processes.
Explanation: Dolomite bricks are classified as basic refractory bricks, known for their excellent resistance to alkaline substances and high temperatures, making them suitable for use in various industrial applications involving exposure to harsh chemical environments and extreme heat, ensuring their durability and long-term performance in challenging operating conditions.
Explanation: Jhamb bricks are typically overburnt, characterized by their dark brown color and distorted shape resulting from excessive exposure to high temperatures during the firing process, indicating the importance of controlling the firing process to ensure the uniform and consistent quality of the bricks produced in various construction activities.
Explanation: Bricks are popular as a construction material due to their affordability, local availability, durability, relatively good strength, and lighter weight compared to stones, along with their excellent insulating properties against heat and sound, making them suitable for use in various construction applications and architectural designs.
Explanation: The most widely used kiln in Nepal is the bull’s trench kiln, known for its efficiency and cost-effectiveness in firing bricks, enabling the production of high-quality and durable bricks that meet the required standards and specifications in various construction projects and infrastructure developments.
Explanation: The size of the bull’s trench kiln is typically elliptical, allowing for the efficient and uniform firing of bricks, ensuring the effective distribution of heat and combustion throughout the kiln, resulting in well-burnt and durable bricks that meet the quality and performance standards required in construction activities.
Explanation: The standard size of the brick as per the Indian standard is 19×9×9 cm, providing the required dimensions and specifications for the production of high-quality bricks that meet the standard size requirements in various construction projects and infrastructure developments.
Explanation: All burnt bricks are soaked in water for at least 4 hours before use with cement mortars, ensuring their proper hydration and saturation, enabling the effective bonding and adherence of the mortar to the bricks during the construction process, resulting in strong and durable masonry structures that meet the required strength and stability standards in various construction activities.
Explanation: For the production of good quality tiles, the soil should ideally contain a maximum percentage of fine sand content of around 40%, ensuring the appropriate composition and consistency required for the manufacturing process, resulting in high-quality and durable tiles suitable for various construction and design applications.
Explanation: The maximum percentage of clay content suitable for the production of good tiles is approximately 30%, ensuring the proper plasticity and workability of the soil material during the tile manufacturing process, leading to the production of high-quality and well-structured tiles with the desired strength and durability properties.
Explanation: The maximum percentage of silt content suitable for the production of good tiles is approximately 30%, ensuring the appropriate texture and composition of the soil material, facilitating the effective shaping and formation of high-quality and well-structured tiles that meet the required standards and specifications in various construction and design applications.
Explanation: The maximum percentage of warping along the sides of tiles is generally around 2%, ensuring the proper dimensional stability and uniformity of the tiles during the manufacturing and curing processes, preventing any significant deformations or distortions that could compromise their structural integrity and quality in various construction and design applications.
Explanation: Finely powdered burnt clay is known as surkhi, commonly used as a supplementary material in cement mortar and concrete mixtures, contributing to the improved workability, strength, and durability of the construction materials in various building and infrastructure projects, ensuring their reliable and long-term performance.
Explanation: A brick is a block of loamy material, typically composed of clay, sand, and other organic materials, subjected to high-temperature firing processes, resulting in the formation of durable and well-structured building blocks used in various construction activities and architectural designs, ensuring their strength and stability in different structural applications.
Explanation: Efflorescence in brick occurs due to an excess of alkalis, resulting in the formation of white or grayish salt deposits on the surface of the bricks, indicating the presence of soluble salts, which can affect the appearance and structural integrity of the bricks, requiring appropriate preventive measures during the manufacturing and curing processes.
Explanation: Zinc white is a material generally not used as an extender in paints, often used as a pigment and additive in various industrial applications, including rubber manufacturing and ceramics production, providing essential properties such as opacity and corrosion resistance, ensuring the durability and performance of the materials in specific applications.
Explanation: The ingredient that gives the desired color to a paint is called the pigment, responsible for imparting the specific color, shade, and tone to the paint, ensuring its aesthetic appeal and visual attractiveness in various decorative and architectural applications, reflecting different design preferences and styles.
Explanation: The paints with white lead base are suitable for the painting of woodwork, providing excellent protection and surface finish to wooden structures and surfaces, ensuring their enhanced durability, weather resistance, and aesthetic appeal in various interior and exterior applications, including furniture and architectural elements.
Explanation: The function of the base of an oil paint is to form the body of the paint, providing the necessary consistency, viscosity, and adhesion required for the effective application and coverage of the paint on various surfaces, ensuring its smooth and uniform appearance and texture in different painting and coating applications.
Explanation: The vehicle used in the case of enamel paints is linseed oil, known for its excellent binding and drying properties, ensuring the proper adhesion and cohesion of the paint film to the painted surface, resulting in a smooth, glossy, and durable finish that enhances the appearance and protection of the painted objects and structures.
Explanation: The main component of oil paint includes the carrier, thinner, and pigment, contributing to the overall composition and performance of the paint, ensuring its proper application, adhesion, color, and durability in various painting and coating applications, including artistic works, decorative finishes, and protective coatings.
Explanation: The pigment in paints gives color to the paint, ensuring its specific hue, shade, and tone, contributing to the aesthetic appeal and visual attractiveness of the painted surface, reflecting different design preferences and styles, and allowing for various decorative and creative expressions in artistic and architectural applications.
Explanation: The commonly used drying oil for oil paints is linseed oil, known for its effective drying and binding properties, ensuring the proper adhesion and cohesion of the paint film to the painted surface, resulting in a smooth, uniform, and durable finish that enhances the appearance and protection of the painted objects and structures.
Explanation: Extenders used in paints are for easy spreading of the paint, facilitating the uniform and consistent application of the paint on various surfaces, ensuring its smooth and seamless coverage, providing enhanced workability, and improving the overall painting experience in different decorative and protective coating applications.
Explanation: The commonly used thinner in oil paints is turpentine, known for its excellent solvent properties and compatibility with oil-based paints, enabling the effective dilution and dispersion of the paint pigments, ensuring their proper application and adhesion to different surfaces, including canvas, wood, and metal.
Explanation: The commonly used thinner in distempers is water, facilitating the proper dilution and application of the distemper paint on various porous and absorbent surfaces, including plastered walls and ceilings, ensuring its effective adhesion and coverage, and providing a smooth and uniform finish in different interior and exterior applications.
Explanation: The base material for distemper is chalk, known for its excellent binding and adhesion properties, ensuring the effective formulation and application of the distemper paint on various interior surfaces, including walls and ceilings, providing a smooth, matte finish that enhances the aesthetic appeal and visual comfort of the living spaces.
Explanation: Distemper is used on plastered surfaces not exposed to weather, providing a smooth, matte finish and an elegant appearance to the interior walls and ceilings, ensuring their enhanced visual appeal and aesthetic charm in various residential and commercial spaces, including homes, offices, and public buildings.
Explanation: Turpentine oil is commonly used in paints as a thinner, helping to reduce the viscosity and thickness of the paint, facilitating its smooth application and coverage on various surfaces, ensuring the uniform and consistent spread of the paint and enhancing its adhesion and durability in different painting and coating applications.
Explanation: The defect in painting over a smooth and glossy surface due to which paint does not stick to the surface is known as blistering, characterized by the formation of blister-like bubbles or bumps on the painted surface, indicating poor adhesion and bonding between the paint film and the underlying substrate, requiring proper surface preparation and priming to prevent such issues.
Explanation: Asbestos paint is highly resistant to fire, known for its exceptional fire-retardant properties and heat insulation capabilities, making it suitable for various fireproofing applications, including the protection and coating of structural elements and surfaces in buildings, factories, and industrial facilities, ensuring their enhanced safety and durability in fire-prone environments.
Explanation: The oily liquid in which the base and pigment are dissolved to form a paint is called the vehicle, serving as the medium for the effective dispersion and suspension of the pigment particles, ensuring their proper mixing and integration into the paint, contributing to the overall consistency, stability, and performance of the paint in different coating applications.
Explanation: The base in a paint has the following functions: it forms the body of the paint, reducing the shrinkage cracks, and reinforcing the films of the paint after it has dried, preventing the penetration of paint to lower surfaces, contributing to the overall stability, adhesion, and durability of the paint film in various painting and coating applications.
Explanation: The cracks in the painted surface extending throughout the thickness of the paint are caused due to various factors, including improper seasoning of the painted wood, excessive use of drier, and the application of too many coats of paint resulting in excessive thickness, leading to the formation of cracks and deformations that can compromise the appearance and integrity of the painted surface.
Explanation: The small areas on the painted surface enclosed by hairline cracks are called crazing, indicating the presence of fine cracks or fissures that do not extend through the entire paint film, resulting from the differential expansion and contraction of the paint layers due to temperature variations and environmental changes, requiring proper surface preparation and maintenance to prevent further deterioration and damage.
Explanation: Lacquer paints are generally applied on structural steel, known for their enhanced durability and protective properties, consisting of resin and nitro-cellulose that contribute to the formation of a hard and glossy finish on the painted surface, ensuring its resistance to corrosion, abrasion, and chemical exposure in various industrial and architectural applications.
Explanation: Lacquer is a spirit varnish, commonly used as a protective coating and finish for various wooden surfaces and materials, providing a glossy and durable surface that enhances the natural beauty and grain of the wood, ensuring its long-term protection and aesthetic appeal in different furniture and decorative applications.
Explanation: The solvent used in cement paints is water, serving as a medium for the effective mixing and dispersion of the cement and pigment particles, ensuring their proper integration and adhesion to the painted surface, providing a durable and weather-resistant finish that enhances the appearance and protection of various masonry and concrete structures.
Explanation: The best primer used for structural steelwork is red lead, known for its exceptional anti-corrosive properties and adhesion capabilities, providing an effective base and protective coating for the steel surfaces, preventing rust and oxidation and ensuring their long-term durability and performance in various industrial and construction applications.
Explanation: The commonly used cement in making cement paints is white cement, known for its high-quality and fine-textured composition, providing a smooth and uniform finish to the painted surfaces, ensuring their enhanced durability and weather resistance in various interior and exterior applications, including masonry, stucco, and architectural finishes.
Explanation: The paint used for automobiles is typically oil paint, known for its excellent adhesion, coverage, and weather resistance, providing a durable and protective coating that enhances the appearance and performance of the automotive surfaces, ensuring their long-term protection and aesthetic appeal in different vehicle applications.
Explanation: Duco is the trade name for cellulose paint, commonly used as a high-quality and durable finish for various automotive and industrial applications, providing a smooth, glossy, and long-lasting coating that enhances the appearance and protection of the painted surfaces, ensuring their resistance to abrasion, chemicals, and weather exposure.
Explanation: The paint which gives illumination during the night is called fluorescent paint, known for its unique light-emitting properties and radiant colors that glow in the dark, providing enhanced visibility and safety in various decorative, commercial, and industrial applications, including signage, safety markings, and artistic displays.
Explanation: The function of paint is to give a clean, colorful, and pleasing surface, increase the life of the painted surface, and protect the surface from corrosion and other weather effects, ensuring its long-term durability and aesthetic appeal in various architectural, industrial, and decorative applications, including buildings, structures, and manufactured goods.
Explanation: The painting work is generally specified by the area of the painted surface, indicating the total surface area to be covered with paint, helping to estimate the quantity of paint required, the duration of the painting job, and the overall cost of the project, ensuring accurate planning and execution of the painting work in different construction and maintenance applications.
Explanation: The paints used in aircraft are typically cellulose paints, known for their lightweight, durable, and high-gloss finish that enhances the aerodynamic performance and visual appeal of the aircraft surfaces, providing excellent protection against corrosion, abrasion, and weather exposure in different aviation and aerospace applications.
Explanation: The defect in painting caused due to the sliding of one layer of paint over another layer is known as alligatoring, characterized by the formation of cracked and wrinkled patterns resembling the scales of an alligator, resulting from the improper application, adhesion, or drying of the paint layers, requiring proper surface preparation and recoating to prevent further issues.
Explanation: The main constituent of varnish is resin, known for its excellent adhesive and protective properties, providing a durable and glossy finish that enhances the appearance and durability of the wooden surfaces, ensuring their resistance to moisture, heat, and abrasion in different furniture, flooring, and interior applications.
Explanation: Varnish is essentially made of both resin and solvent. Resin provides the film-forming properties and protective qualities, while the solvent is used to dissolve the resin and make it applicable as a liquid coating.
Explanation: French polish is made by dissolving the resin in spirit (usually alcohol), and it is commonly used as a finish for wooden surfaces, providing a glossy and durable coating.
Explanation: Snowcem paint is a type of cement paint, used for painting masonry and concrete surfaces, particularly in exterior applications to provide protection against weathering and enhance the appearance.
Explanation: Red lead is a pigment commonly used in paints for its corrosion-resistant properties. It provides protection against rust and corrosion when applied to metal surfaces.
Explanation: The pigment commonly used in the manufacture of cement is iron oxide. Iron oxide pigments are added to cement to give it color and are used in the production of colored concrete.
Explanation: PVC (Pigment Volume Concentration) in paint controls various properties, including gloss, cohesion, adhesion, durability, and washability. It represents the volume of pigment in relation to the total volume of the paint.
Explanation: PVC stands for “Pigment Volume Concentration.” It is a parameter in paints that represents the volume of pigment in relation to the total volume of the paint.
Explanation: A muller is a tool used in paint preparation and is concerned with grinding or mulling the base and pigment to achieve a uniform and consistent paint mixture. It plays a role in grinding and blending the components for proper paint consistency.
Explanation: To give a brilliant finish, spirit varnish is typically used. Spirit varnishes are known for their high-gloss and transparent finishes.
Explanation: Oil varnish is often considered the most durable varnish. It provides a strong and protective finish, making it suitable for various applications requiring long-lasting protection.
Explanation: Red lead can be used as a pigment, base, and drier in paint formulations. It has pigment properties and provides corrosion resistance to the base while acting as a drier to help the paint cure.
Explanation: A prime coat for steelwork can be an oxide of iron paint, a mixture of linseed oil and red lead, or an oxide paint in general. The prime coat helps protect the steel surface and promotes adhesion for subsequent coats.
Explanation: Stucco paints are suitable for stone masonry. They are used to protect and enhance the appearance of masonry surfaces.
Explanation: Radiators of vehicles are often painted with a type of paint suitable for metal surfaces. Plastic paint, which can withstand the high temperatures radiators experience, is commonly used for this purpose.
Explanation: Inert fillers or adulterants are used in paint to achieve both an increase in volume and a reduction in the cost of the paint. These fillers help extend the paint and reduce its overall expense.
Explanation: Oil varnish generally consists of resin, oil, and turpentine. The resin provides the film-forming properties, the oil contributes to its durability, and turpentine is used as the solvent to make it applicable as a liquid coating.
Explanation: The essential constituent of varnish paint is resin. The resin provides the film-forming and protective properties of the varnish.
Explanation: For doors on the exterior wall of a building, enamel paint is often recommended. Enamel paint provides a durable and weather-resistant finish suitable for exterior applications.
Explanation: The type of paint whose main constituent is white or colored cement and is used to protect plastered surfaces, brickwork, and masonry in damp places is called cement paint. It is known for its protective and decorative properties in damp environments.
Explanation: Bronze paint typically has a high reflective property, making it suitable for applications requiring a shiny and reflective surface. It is often used for decorative and protective purposes.
Explanation: Distemper is generally used on walls for decorative purposes. It is a type of paint or coating applied to plastered surfaces to provide a smooth and colored finish.
Explanation: In paints, the pigment is primarily responsible for providing color. It gives the paint its characteristic hue. Durability and other properties are influenced by various components of the paint.
Explanation: Emulsion paints contain polyvinyl acetate as a key component. Emulsion paints are water-based paints that use polyvinyl acetate as a binder to hold the pigment and provide adhesion to surfaces.
Explanation: The liquid part of the paint is called the “vehicle.” It is responsible for carrying the pigment and other components, allowing them to be applied as a liquid coating.
Explanation: Anti-corrosive paint is often black in color. It is used to protect metal surfaces from corrosion and provides a durable, protective coating.
Explanation: Teak is not an endogenous tree. Endogenous trees are typically characterized by having their vascular bundles scattered throughout the stem, unlike exogenous trees like teak.
Explanation: Coconut does not belong to exogenous trees. Exogenous trees have growth rings due to the development of new layers of wood, while coconut trees do not exhibit this characteristic growth pattern.
Explanation: The solution of salts from the soil absorbed by trees, which becomes a viscous solution due to the loss of moisture and action of carbon dioxide, is known as sap. Sap contains nutrients and minerals absorbed by the roots.
Explanation: The inner part of the timber log, known as heartwood, is the portion that is no longer living but has become saturated with natural resins and other substances. It is distinct from the outer sapwood.
Explanation: The age of a tree can be judged by counting the annual rings in a cross-section of the tree trunk. Each ring represents one year of growth.
Explanation: The layer between the bark of the tree and the sapwood, which is not yet converted into wood and contains actively dividing cells, is called the cambium layer. It is responsible for the growth of new wood.
Explanation: Deodar is not a hardwood; it is a type of softwood. Hardwood trees have broad leaves, while softwood trees typically have needle-like or scale-like leaves.
Explanation: Shisham is not a softwood; it is a hardwood. It is a deciduous tree known for its hardwood timber.
Explanation: When timber is attacked by a specific type of fungus (Serpula lacrymans) and reduced to a dry, powdery state, it is referred to as “dry rot.” Dry rot is a common issue that affects the structural integrity of timber.
Explanation: The curved swellings from the growth of layers or wounds left after branches are cut off in an irregular manner are known as “burls.” Burls can have unique and often attractive grain patterns, making them valuable for certain woodworking purposes.
Explanation: The defects in wood due to hardening are not specifically described as knots, rind galls, or burls. The term “hardening” is used to refer to the process of wood becoming harder and more dense as it ages.
Explanation: The defects caused by the shrinkage of timber include crook, cup and bow, and twist. These defects can compromise the structural integrity and aesthetic appeal of the wood.
Explanation: Shisham timber is known for its maximum resistance against white rots, making it a highly durable and sought-after wood for various applications.
Explanation: Dry rot can cause timber to deteriorate and reduce to a powdery state. It is a severe form of decay caused by certain types of fungi that thrive in moist environments.
Explanation: Knots in timber are the signs of branches that have been cut off from the tree trunk. They are circular or oval-shaped marks on the wood caused by the presence of dormant buds or living branches in the tree’s growth.
Explanation: Teak wood has maximum resistance to white ants and is often used in regions where termite infestation is a concern.
Explanation: Creosote oil is used to preserve wood from rot, white ants (termites), and other decay-causing organisms. It is commonly used as a wood preservative.
Explanation: Timber can be made reasonably fire-resistant by soaking it in ammonium sulfate. This process is known as ammonium sulfate treatment and imparts fire resistance to the wood.
Explanation: The main purpose of seasoning is to remove the moisture from the timber at a uniform rate. Seasoning helps reduce the moisture content of the wood, making it suitable for various applications.
Explanation: Seasoning of timber has various benefits, including making the timber light, strong, and stable, preventing warping, cracking, and shrinkage, and making the wood resistant to decay by fungi, termites, and electricity.
Explanation: Seasoning of timber is essential to remove the sap from the timber, reducing its moisture content to a suitable level for various applications.
Explanation: Seasoning of timber is done to decrease the moisture content of the wood. It is done to reduce the moisture to an appropriate level for improved stability, strength, and resistance to decay.
Explanation: The artificial seasoning of timber involves various methods to remove moisture from the wood, improving its properties such as strength, stability, and resistance to decay.
Explanation: The seasoning of timber is done to reduce the moisture content of the wood. It involves drying the timber under controlled conditions to achieve the desired moisture level.
Explanation: Seasoning of timber is done to achieve multiple objectives, including reducing the weight of timber, reducing the chances of shrinkage, and increasing the strength and durability of the wood.
Explanation: The statement “kiln-seasoned timber is stronger than naturally seasoned timber” is not correct. Kiln seasoning does not necessarily make timber stronger than naturally seasoned timber. It primarily reduces moisture content and provides other benefits but doesn’t affect the inherent strength of the wood.
Explanation: In a well-seasoned timber, the moisture content is typically in the range of 10-12%. Seasoning reduces the moisture content to this level to ensure stability and durability.
Explanation: Impregnating of timber is done to increase the fire resistance of the wood. It involves treating the wood with fire-resistant chemicals to make it less susceptible to fire.
Explanation: A freshly felled tree may contain water (moisture) in its tissues, which can be as high as 100% of the wood’s dry weight.
Explanation: The most economical method of sawing wood is flat sawing. This method maximizes the yield of usable lumber from the log and is commonly used in various woodworking operations.
Explanation: A thin sheet of wood sliced from a log of wood is known as veneer. Veneers are commonly used in various woodworking applications and for decorative purposes.
Explanation: Veneering refers to the process of gluing a thin layer of superior wood to an inferior wood surface. This is done to improve the appearance, durability, or other properties of the wood.
Explanation: In the manufacture of plywood, the veneers are placed such that the grains of one layer are at right angles with the grains of the other. This configuration adds strength and stability to the plywood.
Explanation: Plywood is identified by its thickness. The thickness of plywood can vary depending on the intended application and specific requirements of the project.
Explanation: Plywood is obtained by gluing wooden sheets together at specific pressure and temperature specifications. This process ensures that the layers are firmly bonded, resulting in a strong and durable plywood sheet.
Explanation: Plywood is generally available in various thicknesses, with the range typically being around 3 to 4 mm.
Explanation: A piece of sawn timber whose cross-sectional dimensions exceed 5 cm in one direction and 20 cm in the other direction is called a “bauk.”
Explanation: A piece of timber whose thickness and width are respectively 5 cm and 10 cm is called a “strip.”
Explanation: The strength of timber is maximum along the direction parallel to the grain. Timber is typically stronger and more resistant to stress when force is applied in this direction.
Explanation: The defects in the growth of timber are known as “shakes” and “checks.” Shakes refer to defects caused by the separation of wood fibers, while checks are cracks that develop in the timber.
Explanation: The trunk of the tree left after cutting all the branches is known as a “log.”
Explanation: Various chemicals are used in preserving timber, including ZnCl2, HgCl2, coaltar, and creosote oil. These chemicals help protect the wood from decay, pests, and other forms of damage.
Explanation: Shisham is one of the trees that yield hard wood. It is known for its strength, durability, and resistance to decay, making it suitable for various applications.
Explanation: Chir and deodar are examples of trees that yield softwood. Softwood is typically less dense and less durable than hardwood, making it suitable for various applications such as construction and furniture.
Explanation: According to IS399-1963, the weight of the timber is specified at 12% moisture content. This standard ensures uniformity in the measurement of timber weight for various applications.
Explanation: Plywood is primarily made from teakwood, although other types of wood may also be used depending on the specific requirements of the plywood manufacturing process.
Explanation: Sports goods are often made from mulberry wood due to its strength, flexibility, and other desirable properties that make it suitable for various sporting equipment.
Explanation: Teakwood is highly suitable for making furniture due to its durability, resistance to decay, and aesthetic appeal. It is commonly used in the production of high-quality furniture.
Explanation: Rosewood is commonly used for decorative woodwork due to its attractive appearance, rich color, and fine grain, making it ideal for creating aesthetically pleasing and high-quality decorative pieces.
Explanation: The unit weight of sal is approximately 800 kg/m^3. This density measurement is important for various applications where the weight and strength of the wood are essential considerations.
Explanation: Bamboo is often used for scaffolding due to its lightweight, strength, and ease of availability. Its natural properties make it a suitable material for various construction and temporary support structures.
Explanation: First-class timber typically has a longer lifespan, often exceeding 10 years. This type of timber is characterized by its high quality, durability, and resistance to decay and other forms of damage.
Explanation: The timber whose thickness is less than 5 cm and width exceeds 12 cm is called a “board.” Boards are often used for various applications that require thinner pieces of wood.
Explanation: The cracks that extend from the bark towards the sapwood in the cross-section of a tree are known as “star shakes.” These cracks can affect the structural integrity of the wood and may lead to further damage if not addressed.
Explanation: The process of adding water to lime to convert it into hydrated lime is known as “slaking.” This process is essential in various applications where hydrated lime is needed for its chemical properties and reactivity.
Explanation: Quick lime is slow in setting, rapid in slaking, and it generates heat when water is added to it. These properties are characteristic of quick lime and are essential to understand for its proper handling and use in various applications.
Explanation: Lime is primarily obtained from limestone, which is a sedimentary rock composed mainly of calcium carbonate. Limestone is a commonly used raw material for the production of lime and various other materials.
Explanation: Quick lime is chemically known as calcium oxide (CaO). It is a white, alkaline, crystalline solid that is obtained by heating limestone or seashells. Quick lime has various industrial and construction applications.
Explanation: The main constituent that is mainly responsible for hydraulicity, particularly in the context of lime, is clay. Clay is known for its ability to impart hydraulic properties to lime, making it suitable for various applications where hydraulic lime is required.
Explanation: The lime suitable for making mortar is hydraulic lime. Hydraulic lime has the property of setting and hardening under water, making it suitable for use in various construction applications, including mortar preparation.
Explanation: The lime suitable for use underwater is hydraulic lime. This type of lime possesses hydraulic properties, enabling it to set and harden even when submerged in water. It is commonly used in construction projects that involve water exposure.
Explanation: Lime having high calcium oxide content, which can set and become hard only in the presence of CO2 from the atmosphere, is known as fat lime. It is commonly used for various construction and industrial applications where its unique properties are required.
Explanation: Sand is mixed with lime mortar to achieve multiple purposes, including aiding the pure lime to set by allowing the penetration of air, reducing the overall cost of the mortar by increasing the volume, and preventing shrinkage during the setting process.
Explanation: The advantage of adding pozzolana to lime is that it imparts greater strength to the lime mixture. Pozzolana is a finely divided material that, when mixed with lime, enhances the overall strength and performance of the resulting mortar or concrete.
Explanation: Fat lime may be converted into artificial hydraulic lime by the addition of clay in the required proportion. This process helps impart hydraulic properties to the lime, enabling it to set and harden even under water.
Explanation: Very strong lime mortar is obtained from hydraulic lime. Hydraulic lime has the property of setting and hardening under water, making it suitable for use in applications that require high strength and durability.
Explanation: As compared to fat lime, hydraulic lime sets faster. This property of hydraulic lime is crucial in construction projects where quick setting and hardening are required to ensure timely completion and durability of the structure.
Explanation: Lime concrete is commonly used in the construction of floors, particularly under the floors. It is known for its durability, strength, and other desirable properties that make it suitable for providing stable and robust foundations.
Explanation: The quick lime as it comes from kilns is called lump lime. Lump lime is the raw form of quick lime that is produced through the heating of limestone or seashells in kilns. It is further processed to obtain various lime-based products.
Explanation: A dry powder obtained on treating quick lime with just enough water to satisfy its chemical affinity for water under the condition of its hydration is called hydrated lime. Hydrated lime has various industrial and construction applications due to its chemical properties.
Explanation: The quality of lime is checked by the ball test. The ball test involves the formation of a ball using a sample of lime, which is then rolled between the palms to assess its plasticity and other properties, indicating the quality of the lime.
Explanation: The constituent responsible for the setting of hydraulic lime underwater is clay. Clay imparts hydraulic properties to lime, enabling it to set and harden even when submerged in water, making it suitable for various construction applications.
Explanation: A thin pourable suspension of slaked lime in water is known as milk of lime. Milk of lime is commonly used in various industrial processes, including water treatment and chemical manufacturing, due to its alkaline properties.
Explanation: Lime suitable for making mortar of good strength is hydraulic lime. Hydraulic lime has properties that make it suitable for various construction applications that require high-strength mortar, providing durability and stability to structures.
Explanation: A mortar prepared by mixing wood powder or sawdust to the cement or lime mortar is known as lightweight mortar. Lightweight mortar is used in various construction applications where reduced weight and improved insulation properties are desired.
Explanation: Quick lime is obtained by heating or burning limestone (calcium carbonate) at high temperatures, which leads to the decomposition of limestone into quick lime (calcium oxide) and carbon dioxide.
Explanation: The calcination of pure lime results in quick lime (calcium oxide). Calcination is the process of heating limestone to high temperatures to drive off carbon dioxide, leaving behind quick lime.
Explanation: Plaster of Paris can be obtained from the calcination of gypsum. The process of heating gypsum to a specific temperature results in the production of Plaster of Paris, which is used in various construction and medical applications.
Explanation: Silicious and aluminous minerals that can react with lime in the presence of water at normal temperatures to form cementitious compounds are known as pozzolanic materials. These materials contribute to the strength and durability of cementitious products.
Explanation: The process of heating limestone to redness in contact with air is termed calcination. During calcination, limestone is heated to high temperatures, leading to the decomposition of calcium carbonate into quick lime (calcium oxide) and carbon dioxide.
Explanation: The advantage of adding pozzolana to lime includes reducing shrinkage, increasing resistance to cracking, and imparting greater strength to the resulting mixture. Pozzolanic materials enhance the properties of lime mixtures.
Explanation: Bitumen is used for various applications, including waterproofing, damp proofing, and serving as a joint filler. It is a versatile material known for its water-resistant and adhesive properties.
Explanation: Asphalt is a mixture of bitumen and inert mineral matter. It is commonly used in road construction and other applications where a durable and flexible paving material is needed.
Explanation: Plastic asphalt is a mixture of cement and asphalt. It is a type of asphalt concrete mix used in various construction projects, including road paving and other applications.
Explanation: Rubberization temperature is typically around 180°C. This is the temperature range at which rubberized bitumen or asphalt is produced. Rubberized bitumen is used for road construction to improve pavement performance.
Explanation: Bitumen paint is used to provide a protective surface coating. It forms a waterproof and durable protective layer when applied to various surfaces, helping to prevent moisture penetration and other forms of damage.
Explanation: When a bitumen is graded as 75/15, the figure 75 represents the softening point in degrees Celsius (°C). Bitumen grades provide information about various properties of the bitumen, such as its temperature-related characteristics.
Explanation: The softening point test for bitumen is denoted by two numerals (x/y). The upper numeral (x°C) indicates the softening temperature at which the bitumen softens, while the lower numeral (y) indicates the penetration value, which is related to the consistency of the bitumen.
Explanation: Plastic bitumen is generally used for crack filling. It is a type of bitumen that remains pliable and flexible, making it suitable for sealing and filling cracks in road pavements and other surfaces.
Explanation: The commonly used grade of bitumen for the moderate temperature range is 80/100. Bitumen grades like 80/100 indicate specific properties and characteristics suitable for particular temperature conditions and applications.
Explanation: Bitumen is generally obtained from petroleum products. It is a viscous, black or dark brown material derived from crude oil through various refining processes.
Explanation: The weight loss on heating of bitumen used for pavement should not be more than 1%. This property ensures that the bitumen maintains its integrity and performance under heat and load conditions.
Explanation: Galvanizing means depositing a fine film of zinc on iron or steel by dipping it in molten zinc. This process is commonly used to protect iron and steel from corrosion, extending the lifespan of the metal.
Explanation: Brass is an alloy of copper and zinc. It is known for its durability and resistance to corrosion, making it suitable for various applications, including the production of musical instruments and decorative items.
Explanation: Bronze is an alloy of copper and tin. It is a strong and durable material known for its resistance to corrosion and various mechanical properties. Bronze has been used historically for sculptures, coins, and other decorative and functional items.
Explanation: Monel metal is an alloy of copper and nickel. It is known for its high strength and resistance to corrosion, making it suitable for use in various applications, including marine engineering and chemical processing.
Explanation: Stainless steel is an alloy of nickel and chromium. It is known for its high resistance to corrosion and staining, making it suitable for various applications where durability and hygiene are essential, such as kitchen utensils and medical equipment.
Explanation: Stainless steel resists corrosion due to the presence of chromium. Chromium forms a passive layer on the surface of stainless steel, protecting it from corrosion and oxidation, even in harsh environments.
Explanation: German silver is an alloy of copper, zinc, and nickel. Despite its name, German silver does not contain silver but is valued for its silver-like appearance and resistance to corrosion, making it suitable for various decorative and ornamental purposes.
Explanation: The percentage of carbon in cast iron is typically in the range of 2 to 4.5%. Cast iron is known for its high carbon content, which contributes to its strength and brittleness, making it suitable for applications where hardness and wear resistance are required.