Correct Answer - Option 4 : A - II, B - III, C - IV, D - I
Hardness test: In this test, a scratch is made on a brick surface with a hard thing. If that doesn’t leave any impression on brick then that is good quality brick.
Water absorption test: In this test, bricks are weighed in dry condition and let immersed in fresh water for 24 hours. After 24 hours of immersion, those are taken out from the water and wipe out with a cloth. Good quality brick doesn't absorb more than 20% water of its own weight.
Soundness test: In this test two bricks are held by both hands and stuck with one another. If the bricks give a clear metallic ringing sound and don’t break then those are good quality bricks.
Compressive strength test: In this test, a brick specimen is put on a crushing machine and applied pressure till it breaks. The ultimate pressure at which brick is crushed is taken into account.