Bricks MCQ with answer and solution

Concept

The lowest class of common burnt clay bricks in IS 1077 has a minimum compressive strength of 3.5 N/mm².

Formula

1 N/mm² = 1 MPa ≈ 10 kg/cm²

Step-by-step solution

1. IS 1077 covers common burnt clay building bricks. 2. In the 1957 version, the lowest class was 35 kg/cm². 3. 35 kg/cm² ≈ 3.5 N/mm² = 3.5 MPa. 4. So minimum crushing strength > 3.5 MPa, which is option B.

Explanation

IS 1077 classifies bricks by their compressive strength. The lowest class needs about 35 kg/cm², which is 3.5 MPa. So bricks below this strength are not accepted as common building bricks.

Why the other options are wrong

A: 2.5 MPa is below the lowest class in IS 1077. C and D: 4.5 and 5.5 MPa are higher than the minimum, so they are not the minimum value.

Shortcut

Lowest brick class = 35 kg/cm² ≈ 3.5 MPa.

Common mistake

Confusing the value in kg/cm² with N/mm², or picking the strength of a higher class.