Please keep at least one language enabled. || కనీసం ఒక భాషను ఎంచుకోండి.
Question 1
ప్రశ్న 1
Which combination best represents the desirable overall characteristics of a good-quality burnt clay building brick?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A good building brick should combine adequate mechanical strength with durability and dimensional quality rather than excel in only one property.
• Controlled water absorption is important because excessive moisture uptake can adversely affect durability and masonry performance.
• Regular dimensions and reasonably true faces help maintain consistent mortar joints and improve the quality of brickwork.
• The brick should also be compact and sound, without detrimental cracks, flaws, free-lime nodules or excessive soluble-salt effects.
• Therefore Option A represents the balanced set of properties expected from a good-quality building brick.
• Controlled water absorption is important because excessive moisture uptake can adversely affect durability and masonry performance.
• Regular dimensions and reasonably true faces help maintain consistent mortar joints and improve the quality of brickwork.
• The brick should also be compact and sound, without detrimental cracks, flaws, free-lime nodules or excessive soluble-salt effects.
• Therefore Option A represents the balanced set of properties expected from a good-quality building brick.
వివరణ:
Question 2
ప్రశ్న 2
A common burnt clay brick is designated as Class 20 under IS 1077:2025. Which property is directly represented by the class designation?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The class designation of a common burnt clay building brick is based on its minimum average compressive strength.
• Thus a Class 20 brick requires a minimum average compressive strength of 20 N/mm² under the prescribed test conditions.
• The number 20 does not represent the permitted water absorption percentage.
• Modulus of rupture and initial rate of absorption are separate physical requirements and are not encoded directly in the class designation.
• Therefore Option B correctly interprets the engineering meaning of Class 20.
• Thus a Class 20 brick requires a minimum average compressive strength of 20 N/mm² under the prescribed test conditions.
• The number 20 does not represent the permitted water absorption percentage.
• Modulus of rupture and initial rate of absorption are separate physical requirements and are not encoded directly in the class designation.
• Therefore Option B correctly interprets the engineering meaning of Class 20.
వివరణ:
Question 3
ప్రశ్న 3
For a Class 25 common burnt clay brick, what is the lowest individual compressive strength permitted if an individual brick is allowed to fall not more than 15 percent below the corresponding class strength?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The corresponding class strength is 25 N/mm².
• The maximum permitted reduction for an individual tested brick is 15 percent of the class strength.
• Fifteen percent of 25 N/mm² is 3.75 N/mm².
• Therefore the lower individual limit is 25 − 3.75 = 21.25 N/mm².
• Hence Option C is correct, while the average strength of the sample must independently satisfy the Class 25 average-strength requirement.
• The maximum permitted reduction for an individual tested brick is 15 percent of the class strength.
• Fifteen percent of 25 N/mm² is 3.75 N/mm².
• Therefore the lower individual limit is 25 − 3.75 = 21.25 N/mm².
• Hence Option C is correct, while the average strength of the sample must independently satisfy the Class 25 average-strength requirement.
వివరణ:
Question 4
ప్రశ్న 4
A brick has a dry mass of 2.50 kg and a mass of 2.85 kg after the prescribed 24-hour immersion. What is its water absorption by dry mass?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Water absorption is calculated as [(wet mass − dry mass) / dry mass] × 100.
• The increase in mass is 2.85 − 2.50 = 0.35 kg.
• Dividing 0.35 kg by the dry mass of 2.50 kg gives 0.14.
• Multiplication by 100 gives a water absorption of 14 percent by dry mass.
• Therefore Option B is correct, and this numerical value must then be compared with the limit applicable to the brick's strength class.
• The increase in mass is 2.85 − 2.50 = 0.35 kg.
• Dividing 0.35 kg by the dry mass of 2.50 kg gives 0.14.
• Multiplication by 100 gives a water absorption of 14 percent by dry mass.
• Therefore Option B is correct, and this numerical value must then be compared with the limit applicable to the brick's strength class.
వివరణ:
Question 5
ప్రశ్న 5
Which statement correctly describes the water-absorption limits for common burnt clay building bricks under IS 1077:2025 after the specified 24-hour immersion?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• IS 1077:2025 relates the permissible water absorption to the compressive-strength class of the brick.
• For classes up to and including Class 12.5, water absorption after the prescribed 24-hour immersion shall not exceed 20 percent by dry weight.
• For classes higher than 12.5, the corresponding maximum is 15 percent by weight.
• This distinction reflects the more stringent physical-quality requirement imposed on the higher-strength brick classes.
• Therefore Option A correctly states the class-dependent water-absorption limits.
• For classes up to and including Class 12.5, water absorption after the prescribed 24-hour immersion shall not exceed 20 percent by dry weight.
• For classes higher than 12.5, the corresponding maximum is 15 percent by weight.
• This distinction reflects the more stringent physical-quality requirement imposed on the higher-strength brick classes.
• Therefore Option A correctly states the class-dependent water-absorption limits.
వివరణ:
Question 6
ప్రశ్న 6
Two bricks have the same dimensions and satisfy their specified compressive-strength requirement. Brick X absorbs 11 percent water by dry mass, while Brick Y absorbs 24 percent. Which interpretation is most technically appropriate?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Water absorption provides useful information about the ability of a brick to take up moisture and is related to its pore structure.
• Excessively high absorption can indicate a more open pore system and can adversely affect durability and moisture behaviour in masonry.
• An absorption value must nevertheless be assessed against the limit applicable to the particular brick specification and class rather than by an arbitrary universal rule.
• Adequate compressive strength does not make water absorption irrelevant because the properties control different aspects of performance.
• Therefore Option C gives the technically appropriate interpretation without claiming that absorption alone completely determines durability.
• Excessively high absorption can indicate a more open pore system and can adversely affect durability and moisture behaviour in masonry.
• An absorption value must nevertheless be assessed against the limit applicable to the particular brick specification and class rather than by an arbitrary universal rule.
• Adequate compressive strength does not make water absorption irrelevant because the properties control different aspects of performance.
• Therefore Option C gives the technically appropriate interpretation without claiming that absorption alone completely determines durability.
వివరణ:
Question 7
ప్రశ్న 7
A Class 10 common burnt clay brick receives an efflorescence rating of 'moderate'. Based on the efflorescence requirement of IS 1077:2025, which conclusion is correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Class 10 falls within the group of common burnt clay bricks up to and including Class 12.5.
• For this group, IS 1077:2025 requires the efflorescence rating to be not more than moderate.
• A rating of moderate is therefore at the limiting acceptable level for the stated class.
• Higher strength classes above Class 12.5 are subjected to the more stringent requirement of not more than slight efflorescence.
• Hence the Class 10 brick described in the question satisfies the specified efflorescence criterion and Option B is correct.
• For this group, IS 1077:2025 requires the efflorescence rating to be not more than moderate.
• A rating of moderate is therefore at the limiting acceptable level for the stated class.
• Higher strength classes above Class 12.5 are subjected to the more stringent requirement of not more than slight efflorescence.
• Hence the Class 10 brick described in the question satisfies the specified efflorescence criterion and Option B is correct.
వివరణ:
Question 8
ప్రశ్న 8
A Class 20 common burnt clay brick is found to have a 'moderate' efflorescence rating. What is the correct assessment under IS 1077:2025?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Class 20 is higher than Class 12.5 and therefore falls within the more stringent efflorescence category of IS 1077:2025.
• For such higher classes, the permitted efflorescence rating is not more than slight.
• A moderate rating exceeds the permitted degree and therefore does not comply with the stated requirement.
• Adequate compressive strength cannot compensate automatically for failure of an independent physical requirement such as efflorescence.
• Consequently Option B is the correct assessment.
• For such higher classes, the permitted efflorescence rating is not more than slight.
• A moderate rating exceeds the permitted degree and therefore does not comply with the stated requirement.
• Adequate compressive strength cannot compensate automatically for failure of an independent physical requirement such as efflorescence.
• Consequently Option B is the correct assessment.
వివరణ:
Question 9
ప్రశ్న 9
Which mechanism best explains visible efflorescence on brick masonry?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Efflorescence is associated with soluble salts present in the brick, mortar, surrounding materials or moisture source.
• Water dissolves these salts and transports them through the pore system toward an exposed surface.
• When the water evaporates, the salts remain and crystallize as visible whitish or grey deposits.
• The phenomenon therefore depends on both a source of soluble salts and moisture movement through the masonry.
• Option A correctly describes this mechanism, whereas the other options are unrelated to salt crystallization.
• Water dissolves these salts and transports them through the pore system toward an exposed surface.
• When the water evaporates, the salts remain and crystallize as visible whitish or grey deposits.
• The phenomenon therefore depends on both a source of soluble salts and moisture movement through the masonry.
• Option A correctly describes this mechanism, whereas the other options are unrelated to salt crystallization.
వివరణ:
Question 10
ప్రశ్న 10
For a common burnt clay brick having a height of 90 mm, what is the maximum permissible average warpage under IS 1077:2025?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• IS 1077:2025 limits average warpage to 3 mm or 5 percent of the brick height, whichever is lower.
• For a 90 mm high brick, 5 percent of the height is 0.05 × 90 = 4.5 mm.
• The two possible limits are therefore 3 mm and 4.5 mm.
• The lower value is 3 mm, so that value governs the allowable average warpage.
• Consequently Option B is correct.
• For a 90 mm high brick, 5 percent of the height is 0.05 × 90 = 4.5 mm.
• The two possible limits are therefore 3 mm and 4.5 mm.
• The lower value is 3 mm, so that value governs the allowable average warpage.
• Consequently Option B is correct.
వివరణ:
Question 11
ప్రశ్న 11
For a 40 mm high modular common burnt clay brick, what average warpage limit governs under IS 1077:2025?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The standard limits average warpage to the lower of 3 mm and 5 percent of the brick height.
• Five percent of a 40 mm brick height is 0.05 × 40 = 2 mm.
• Comparing 2 mm with the absolute limit of 3 mm shows that 2 mm is lower.
• Therefore the permissible average warpage for this brick height is 2 mm.
• Option B is correct and illustrates why the percentage-based limit becomes controlling for thin bricks.
• Five percent of a 40 mm brick height is 0.05 × 40 = 2 mm.
• Comparing 2 mm with the absolute limit of 3 mm shows that 2 mm is lower.
• Therefore the permissible average warpage for this brick height is 2 mm.
• Option B is correct and illustrates why the percentage-based limit becomes controlling for thin bricks.
వివరణ:
Question 12
ప్రశ్న 12
A sample of 40 mm high common burnt clay bricks has an average measured warpage of 2.2 mm. Which conclusion is correct under IS 1077:2025?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• For a 40 mm high brick, 5 percent of the brick height is 2 mm.
• The standard requires the average warpage to be no more than 3 mm or 5 percent of height, whichever is lower.
• Therefore the governing limit is 2 mm rather than 3 mm.
• The measured average value of 2.2 mm exceeds this permissible limit.
• Hence the sample fails the warpage requirement and Option B is correct.
• The standard requires the average warpage to be no more than 3 mm or 5 percent of height, whichever is lower.
• Therefore the governing limit is 2 mm rather than 3 mm.
• The measured average value of 2.2 mm exceeds this permissible limit.
• Hence the sample fails the warpage requirement and Option B is correct.
వివరణ:
Question 13
ప్రశ్న 13
A brick sample has an average compressive strength of 20 N/mm² and an average modulus of rupture of 1.6 N/mm². Based on the modulus-of-rupture requirement in IS 1077:2025, which conclusion is correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The relevant requirement compares the average modulus of rupture with the compressive strength through their ratio.
• For the given values, the ratio is 1.6 / 20 = 0.08.
• IS 1077:2025 requires this ratio to be greater than 0.07.
• Since 0.08 exceeds 0.07, the stated sample satisfies this particular physical requirement.
• Therefore Option B is correct, assuming the other independent specification requirements are also met.
• For the given values, the ratio is 1.6 / 20 = 0.08.
• IS 1077:2025 requires this ratio to be greater than 0.07.
• Since 0.08 exceeds 0.07, the stated sample satisfies this particular physical requirement.
• Therefore Option B is correct, assuming the other independent specification requirements are also met.
వివరణ:
Question 14
ప్రశ్న 14
If a brick sample has an average compressive strength of 30 N/mm², what must be true of its average modulus of rupture to satisfy the IS 1077:2025 ratio requirement?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The standard requires the ratio of average modulus of rupture to compressive strength to be greater than 0.07.
• For a compressive strength of 30 N/mm², 0.07 × 30 = 2.1 N/mm².
• A modulus of rupture exactly equal to 2.1 N/mm² would give a ratio of exactly 0.07.
• Because the requirement is greater than 0.07 rather than greater than or equal to 0.07, the modulus of rupture must exceed 2.1 N/mm².
• Therefore Option C is the only answer consistent with the stated ratio requirement.
• For a compressive strength of 30 N/mm², 0.07 × 30 = 2.1 N/mm².
• A modulus of rupture exactly equal to 2.1 N/mm² would give a ratio of exactly 0.07.
• Because the requirement is greater than 0.07 rather than greater than or equal to 0.07, the modulus of rupture must exceed 2.1 N/mm².
• Therefore Option C is the only answer consistent with the stated ratio requirement.
వివరణ:
Question 15
ప్రశ్న 15
A set of common burnt clay bricks gives an average initial rate of absorption of 42 N/m²/min when tested by the prescribed method. What is the correct assessment under IS 1077:2025?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• IS 1077:2025 includes an explicit requirement for the initial rate of absorption of common burnt clay bricks.
• The average IRA value is required to be less than 40 N/m²/min when tested according to the prescribed method.
• The measured value of 42 N/m²/min is greater than that limit.
• Compliance with the separate 24-hour water-absorption requirement would not cancel failure of the IRA requirement because the two properties describe different aspects of water uptake.
• Therefore the brick sample fails this particular requirement and Option B is correct.
• The average IRA value is required to be less than 40 N/m²/min when tested according to the prescribed method.
• The measured value of 42 N/m²/min is greater than that limit.
• Compliance with the separate 24-hour water-absorption requirement would not cancel failure of the IRA requirement because the two properties describe different aspects of water uptake.
• Therefore the brick sample fails this particular requirement and Option B is correct.
వివరణ:
Question 16
ప్రశ్న 16
Why is an excessively high initial rate of absorption undesirable when bricks are laid in mortar?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Initial rate of absorption describes how rapidly a relatively dry brick can take up water through its contact surface.
• If the rate is excessive, the brick can draw water quickly from fresh mortar at the interface.
• Excessive suction can reduce the time available for proper wetting, spreading and bond development unless construction practice appropriately compensates for it.
• IRA is therefore different from total 24-hour water absorption, even though both are related to the pore system of the brick.
• Option A correctly identifies the practical masonry significance of controlling initial absorption.
• If the rate is excessive, the brick can draw water quickly from fresh mortar at the interface.
• Excessive suction can reduce the time available for proper wetting, spreading and bond development unless construction practice appropriately compensates for it.
• IRA is therefore different from total 24-hour water absorption, even though both are related to the pore system of the brick.
• Option A correctly identifies the practical masonry significance of controlling initial absorption.
వివరణ:
Question 17
ప్రశ్న 17
During visual inspection, several bricks contain visible nodules of free lime but otherwise appear rectangular and well burnt. Which assessment is most appropriate?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• General quality requirements for common burnt clay bricks include freedom from detrimental cracks, flaws and nodules of free lime.
• Free lime particles can undergo undesirable volume changes when they become hydrated after firing.
• Such local expansion may cause popping, disintegration or surface damage in affected bricks.
• A brick being rectangular or visually well burnt does not make the presence of free-lime nodules desirable.
• Therefore Option B correctly identifies the observed feature as a quality defect.
• Free lime particles can undergo undesirable volume changes when they become hydrated after firing.
• Such local expansion may cause popping, disintegration or surface damage in affected bricks.
• A brick being rectangular or visually well burnt does not make the presence of free-lime nodules desirable.
• Therefore Option B correctly identifies the observed feature as a quality defect.
వివరణ:
Question 18
ప్రశ్న 18
Why are regular shape, reasonably plane faces and sharp corners desirable properties of bricks used in high-quality masonry?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Regular brick geometry assists the mason in maintaining straight, level and uniform courses.
• Reasonably plane faces and true edges help control the thickness and continuity of mortar joints.
• Dimensional irregularity can require excessive mortar adjustment and can contribute to poor alignment or uneven wall surfaces.
• Shape quality does not eliminate the need for mortar and does not make a porous ceramic unit waterproof.
• Therefore Option A correctly explains the construction significance of dimensional and shape quality.
• Reasonably plane faces and true edges help control the thickness and continuity of mortar joints.
• Dimensional irregularity can require excessive mortar adjustment and can contribute to poor alignment or uneven wall surfaces.
• Shape quality does not eliminate the need for mortar and does not make a porous ceramic unit waterproof.
• Therefore Option A correctly explains the construction significance of dimensional and shape quality.
వివరణ:
Question 19
ప్రశ్న 19
A brick surface is scratched firmly with a fingernail and no noticeable impression is produced. What does this traditional field observation primarily indicate?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Resistance to noticeable scratching is traditionally used as a simple field indication of brick surface hardness.
• A hard, well-fired brick should not be readily marked by an ordinary fingernail scratch.
• This observation is qualitative and does not determine the brick's exact compressive strength in N/mm².
• It also cannot quantify water absorption or establish the absence of soluble salts responsible for efflorescence.
• Therefore Option A correctly identifies what the traditional scratch observation can reasonably indicate.
• A hard, well-fired brick should not be readily marked by an ordinary fingernail scratch.
• This observation is qualitative and does not determine the brick's exact compressive strength in N/mm².
• It also cannot quantify water absorption or establish the absence of soluble salts responsible for efflorescence.
• Therefore Option A correctly identifies what the traditional scratch observation can reasonably indicate.
వివరణ:
Question 20
ప్రశ్న 20
When two apparently sound burnt clay bricks are struck lightly against each other, a clear ringing sound rather than a dull sound is traditionally taken as an indication of:
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A clear ringing sound when two bricks are struck together is a traditional field indication of a reasonably sound and well-burnt brick.
• A dull response can suggest internal cracking, inadequate firing or other defects, although the observation is qualitative.
• The field soundness check cannot determine a precise compressive-strength class.
• It also does not demonstrate zero porosity or zero water absorption, because normal burnt clay bricks remain porous materials.
• Therefore Option A gives the appropriate interpretation without overstating the reliability of the field test.
• A dull response can suggest internal cracking, inadequate firing or other defects, although the observation is qualitative.
• The field soundness check cannot determine a precise compressive-strength class.
• It also does not demonstrate zero porosity or zero water absorption, because normal burnt clay bricks remain porous materials.
• Therefore Option A gives the appropriate interpretation without overstating the reliability of the field test.
వివరణ:
Question 21
ప్రశ్న 21
Which statement correctly distinguishes traditional field-quality checks from standardized laboratory tests for bricks?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Field observations such as scratching the surface or striking two bricks together are convenient preliminary indicators of quality.
• They are qualitative checks and do not provide standardized quantitative measurements of structural or moisture-related properties.
• Compressive strength, water absorption and efflorescence are evaluated using prescribed test methods under the relevant IS 3495 series.
• Formal product conformity therefore cannot be established solely by a ringing sound, scratch resistance or visual appearance.
• Option A correctly separates practical field screening from standardized laboratory verification.
• They are qualitative checks and do not provide standardized quantitative measurements of structural or moisture-related properties.
• Compressive strength, water absorption and efflorescence are evaluated using prescribed test methods under the relevant IS 3495 series.
• Formal product conformity therefore cannot be established solely by a ringing sound, scratch resistance or visual appearance.
• Option A correctly separates practical field screening from standardized laboratory verification.
వివరణ:
Question 22
ప్రశ్న 22
When a brick is broken to inspect its interior, which appearance is most consistent with a good-quality brick?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Breaking a brick and examining its cross-section is a traditional practical way of assessing the uniformity of its internal structure.
• A good brick should show a reasonably homogeneous and compact interior rather than obvious internal discontinuities.
• Large cavities, loose clay pockets, harmful inclusions or prominent lumps can indicate poor preparation, moulding or burning.
• Large free-lime nodules are also undesirable because they can cause expansion-related damage when hydrated.
• Therefore Option A represents the internal structure expected from a sound good-quality brick.
• A good brick should show a reasonably homogeneous and compact interior rather than obvious internal discontinuities.
• Large cavities, loose clay pockets, harmful inclusions or prominent lumps can indicate poor preparation, moulding or burning.
• Large free-lime nodules are also undesirable because they can cause expansion-related damage when hydrated.
• Therefore Option A represents the internal structure expected from a sound good-quality brick.
వివరణ:
Question 23
ప్రశ్న 23
Which statement about the colour of burnt clay bricks is the most technically defensible?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Uniformity of colour is a recognized visual-quality characteristic of common burnt clay bricks.
• Colour can provide a useful indication of reasonably consistent raw material and firing conditions within a batch.
• However, the exact shade varies with the mineral composition of the clay and firing process, so one universal shade cannot define all good bricks.
• Colour does not quantitatively establish compressive strength, absorption, efflorescence or other specification requirements.
• Therefore Option A provides the balanced interpretation of colour as a useful but insufficient quality indicator.
• Colour can provide a useful indication of reasonably consistent raw material and firing conditions within a batch.
• However, the exact shade varies with the mineral composition of the clay and firing process, so one universal shade cannot define all good bricks.
• Colour does not quantitatively establish compressive strength, absorption, efflorescence or other specification requirements.
• Therefore Option A provides the balanced interpretation of colour as a useful but insufficient quality indicator.
వివరణ:
Question 24
ప్రశ్న 24
Consider the following statements about brick durability and moisture-related properties:
1. Excessive water absorption may be associated with an open pore structure and greater moisture ingress.
2. Efflorescence involves soluble salts and moisture movement.
3. A brick that meets compressive-strength requirements automatically satisfies every durability-related requirement.
4. Water absorption and efflorescence are separate properties and should be assessed independently.
Which statements are correct?
1. Excessive water absorption may be associated with an open pore structure and greater moisture ingress.
2. Efflorescence involves soluble salts and moisture movement.
3. A brick that meets compressive-strength requirements automatically satisfies every durability-related requirement.
4. Water absorption and efflorescence are separate properties and should be assessed independently.
Which statements are correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Statement 1 is correct because higher water absorption commonly reflects a pore structure capable of taking up greater quantities of moisture.
• Statement 2 is correct because soluble salts must be transported by moisture before they can crystallize at or near a masonry surface as efflorescence.
• Statement 3 is incorrect because compressive strength is only one property and does not establish compliance with absorption, efflorescence, warpage or other requirements.
• Statement 4 is correct because water absorption and efflorescence measure different aspects of brick behaviour and have separate acceptance criteria.
• Therefore Statements 1, 2 and 4 are correct, making Option B the unique answer.
• Statement 2 is correct because soluble salts must be transported by moisture before they can crystallize at or near a masonry surface as efflorescence.
• Statement 3 is incorrect because compressive strength is only one property and does not establish compliance with absorption, efflorescence, warpage or other requirements.
• Statement 4 is correct because water absorption and efflorescence measure different aspects of brick behaviour and have separate acceptance criteria.
• Therefore Statements 1, 2 and 4 are correct, making Option B the unique answer.
వివరణ:
Question 25
ప్రశ్న 25
Match the property or observation with its most appropriate interpretation:
1. Fingernail produces no noticeable scratch
2. Clear ringing sound when two bricks are struck
3. White crystalline surface deposit after moisture movement
4. Homogeneous compact broken cross-section
P. Efflorescence
Q. Surface hardness
R. Soundness field indication
S. Good internal structure
1. Fingernail produces no noticeable scratch
2. Clear ringing sound when two bricks are struck
3. White crystalline surface deposit after moisture movement
4. Homogeneous compact broken cross-section
P. Efflorescence
Q. Surface hardness
R. Soundness field indication
S. Good internal structure
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A surface that resists noticeable fingernail scratching provides a traditional indication of adequate hardness, so 1-Q is correct.
• A clear ringing sound on striking two bricks is used as a field indication of soundness, giving 2-R.
• White crystalline deposits associated with transported soluble salts represent efflorescence, giving 3-P.
• A homogeneous and compact fracture surface is characteristic of good internal structure, so 4-S is correct.
• The complete matching is therefore 1-Q, 2-R, 3-P and 4-S, which corresponds to Option A.
• A clear ringing sound on striking two bricks is used as a field indication of soundness, giving 2-R.
• White crystalline deposits associated with transported soluble salts represent efflorescence, giving 3-P.
• A homogeneous and compact fracture surface is characteristic of good internal structure, so 4-S is correct.
• The complete matching is therefore 1-Q, 2-R, 3-P and 4-S, which corresponds to Option A.
వివరణ:
Question 26
ప్రశ్న 26
A Class 15 common burnt clay brick sample has 14.6 percent water absorption, a 'moderate' efflorescence rating, an average warpage of 2.5 mm for 70 mm high bricks, an average modulus of rupture of 1.20 N/mm² with an average compressive strength of 15.5 N/mm², and an average initial rate of absorption of 37 N/m²/min. Which property causes the sample to fail the stated IS 1077:2025 physical requirements?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Class 15 is above Class 12.5, so its maximum permitted 24-hour water absorption is 15 percent; the measured 14.6 percent therefore complies.
• Higher classes require an efflorescence rating of not more than slight, so a moderate rating fails the efflorescence requirement.
• For a 70 mm high brick, 5 percent of the height is 3.5 mm and the alternative absolute limit is 3 mm, so the governing warpage limit is 3 mm; the measured 2.5 mm complies.
• The modulus-of-rupture ratio is 1.20 / 15.5 ≈ 0.077, which is greater than 0.07, and the IRA of 37 N/m²/min is below the 40 N/m²/min limit.
• Therefore efflorescence is the property that causes failure in the stated data, making Option B correct.
• Higher classes require an efflorescence rating of not more than slight, so a moderate rating fails the efflorescence requirement.
• For a 70 mm high brick, 5 percent of the height is 3.5 mm and the alternative absolute limit is 3 mm, so the governing warpage limit is 3 mm; the measured 2.5 mm complies.
• The modulus-of-rupture ratio is 1.20 / 15.5 ≈ 0.077, which is greater than 0.07, and the IRA of 37 N/m²/min is below the 40 N/m²/min limit.
• Therefore efflorescence is the property that causes failure in the stated data, making Option B correct.
వివరణ:
Question 27
ప్రశ్న 27
A brick possesses very high compressive strength but has irregular dimensions, excessive warpage and poor surface quality. Which engineering conclusion is most appropriate?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Compressive strength is an important engineering property, but it is not the sole criterion governing the quality of a building brick.
• Excessive dimensional variation and warpage can make it difficult to maintain uniform courses and consistent mortar-joint thickness.
• Poor surface and shape quality may also impair workmanship, appearance and dimensional control in completed masonry.
• Product specifications therefore include dimensional and other physical requirements in addition to compressive strength.
• Option B correctly recognizes that a good masonry unit must provide balanced performance rather than high strength alone.
• Excessive dimensional variation and warpage can make it difficult to maintain uniform courses and consistent mortar-joint thickness.
• Poor surface and shape quality may also impair workmanship, appearance and dimensional control in completed masonry.
• Product specifications therefore include dimensional and other physical requirements in addition to compressive strength.
• Option B correctly recognizes that a good masonry unit must provide balanced performance rather than high strength alone.
వివరణ:
Answer Key సమాధానాల పట్టిక
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Question 1 ప్రశ్న 1Answer: A. Adequate strength, controlled water absorption, dimensional regularity, sound structure and limited efflorescence సమాధానం: A.
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Question 2 ప్రశ్న 2Answer: B. Minimum average compressive strength of 20 N/mm² సమాధానం: B.
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Question 3 ప్రశ్న 3Answer: C. 21.25 N/mm² సమాధానం: C.
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Question 4 ప్రశ్న 4Answer: B. 14 percent సమాధానం: B.
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Question 5 ప్రశ్న 5Answer: A. Not more than 20 percent for classes up to 12.5 and not more than 15 percent for higher classes సమాధానం: A.
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Question 6 ప్రశ్న 6Answer: C. Brick X exhibits lower moisture uptake, while Brick Y's high absorption may indicate excessive porosity and requires comparison with the applicable specification. సమాధానం: C.
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Question 7 ప్రశ్న 7Answer: B. It satisfies the efflorescence limit applicable to Class 10. సమాధానం: B.
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Question 8 ప్రశ్న 8Answer: B. It fails the efflorescence requirement because bricks above Class 12.5 are limited to not more than slight efflorescence. సమాధానం: B.
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Question 9 ప్రశ్న 9Answer: A. Soluble salts are transported by moisture and are deposited near the surface when the water evaporates. సమాధానం: A.
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Question 10 ప్రశ్న 10Answer: B. 3.0 mm సమాధానం: B.
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Question 11 ప్రశ్న 11Answer: B. 2 mm సమాధానం: B.
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Question 12 ప్రశ్న 12Answer: B. It fails because the applicable limit is 2.0 mm. సమాధానం: B.
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Question 13 ప్రశ్న 13Answer: B. It satisfies the requirement because the ratio is 0.08, which is greater than 0.07. సమాధానం: B.
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Question 14 ప్రశ్న 14Answer: C. It must be greater than 2.1 N/mm². సమాధానం: C.
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Question 15 ప్రశ్న 15Answer: B. It fails because the average initial rate of absorption is required to be less than 40 N/m²/min. సమాధానం: B.
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Question 16 ప్రశ్న 16Answer: A. It may cause the brick to withdraw water rapidly from fresh mortar and adversely affect the development of the brick-mortar interface. సమాధానం: A.
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Question 17 ప్రశ్న 17Answer: B. The bricks exhibit an undesirable defect because good common burnt clay bricks should be free from nodules of free lime. సమాధానం: B.
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Question 18 ప్రశ్న 18Answer: A. They help obtain uniform courses and mortar joints and improve alignment and workmanship. సమాధానం: A.
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Question 19 ప్రశ్న 19Answer: A. Adequate surface hardness సమాధానం: A.
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Question 20 ప్రశ్న 20Answer: A. general soundness and good firing సమాధానం: A.
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Question 21 ప్రశ్న 21Answer: A. The fingernail scratch and ringing-sound observations are useful field indicators, while compressive strength, water absorption and efflorescence are determined by prescribed standardized test procedures. సమాధానం: A.
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Question 22 ప్రశ్న 22Answer: A. A homogeneous and compact structure substantially free from cavities, large lumps and obvious internal defects సమాధానం: A.
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Question 23 ప్రశ్న 23Answer: A. Uniform colour is a useful indicator of reasonably uniform manufacture and firing, but colour alone cannot establish strength or complete specification compliance. సమాధానం: A.
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Question 24 ప్రశ్న 24Answer: B. 1, 2 and 4 only సమాధానం: B.
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Question 25 ప్రశ్న 25Answer: A. 1-Q, 2-R, 3-P, 4-S సమాధానం: A.
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Question 26 ప్రశ్న 26Answer: B. Efflorescence సమాధానం: B.
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Question 27 ప్రశ్న 27Answer: B. The brick may still be unsuitable for quality masonry because strength alone does not compensate for dimensional and workmanship-related deficiencies. సమాధానం: B.