1. Which of the following is not a chemical change that takes place in the brick earth during burning?
a) Dehydration
b) Vitrification
c) Oxidation
d) Reduction
Explanation: During burning, no reduction reaction takes place. Dehydration expels most of the water. Oxidation results in the elimination of carbon and sulphur as oxides. Vitrification is extreme reaction and occurs when heating above 900oc.
2. The depression provided in the face of a brick during its manufacturing is called:
a) Frog
b) Furrow
c) Groove
d) Scallop
Explanation: Frog is the depression provided in the face of the brick. It forms a key of mortar, reduces the weight of the brick, provides the place for companies to put their trade mark.
3.What is the recommended size of a brick?
a) 20x10x10cm
b) 20x9x9cm
c) 19x9x9cm
d) 19x8x8cm
Explanation: Bureau of Indian Standards recommends the size of a standard brick to be 19x9x9cm. 20x10x10cm is the size of the brick including mortar.
4. A good brick should not absorb more than what percent of water when soaked?
a) 15%
b) 20%
c) 30%
d) 10%
Explanation: As per IS codes when a brick is soaked in water for 24 hours, it should not absorb more than 15% of its dry weight.
5.Which of the following bricks is not preferred?
a) Sharp-edged
b) Clamp burned
c) Sound-proofed
d) Kiln burned
Explanation: In clamp burning, bricks are not burnt uniformly. This results in a non-uniform surface, colour of bricks, which cannot be used for high end works.
6. Which of the below is used to sound proof bricks?
a) Gypsum
b) Terracotta
c) Plastics
d) Ceramic
Explanation: Terracotta is an acoustic material. It will absorb the sound waves and render the brick sound proof.
7. The compressive strength of the brick should be:
a) Minimum 3.5 kN/m2
b) Maximum 3.5 kN/m2
c) Minimum 3.5 N/mm2
d) Maximum 3.5 N/mm2
Explanation: As per IS codes, number of bricks are tested in CTM and average is taken. It should be a minimum of 3.5 N/mm2.
8.A good brick when dropped from the height of 1 metre can:
a) Shatter
b) Not break
c) Break into 2 halves
d) Develop small cracks
Explanation: A good brick should be able to withstand rough handling and transporting. If it breaks into pieces, then it cannot be trusted for use for high strength requirements.
9. What should be observed when a brick is broken?
a) Parallel strata
b) Homogeneous surface
c) Pores
d) Brown colour
Explanation: Brick should have uniform red coloured and homogeneous strata. It should not have any visible pores.
10. Which of the following ranges of dimensions of a good quality brick is correct?
a) Length: 368-392cm
b) Width: 180-210cm
c) Height: 180-210cm
d) Weight: 25-30N
Explanation: The width and height of brick should be in the range of 174-186cm. The weight of 1m3 of brick earth is 18kN. Hence, the average weight of brick should be in the range 30-35N.