86) Jhama bricks are

• (a) well burnt having smooth and even surface
• (b) slightly over burnt having rough surface
• (c) under burnt and can be easily broken
• (d) over burnt with irregular shape

87) The compressive strength of perforated bricks should not be less than

• (a) 4 MN/m2
• (b) 5 MN/m2
• (c) 6 MN/m2
• (d) 7 MN/m2

88) The compressive strength of paving bricks should not be less than

• (a) 20 MN/m2
• (b) 30 MN/m2
• (c) 40 MN/m2
• (d) 50 MN/m2

89) The length of a curved tile varies from

• (a) 10 to 12 cm
• (b) 12 to 15 cm
• (c) 15 to 20 cm
• (d) 20 to 22.5 cm

90) Which of the following statement is wrong ?

• (a) The pan tiles are similar to pot tiles, but are less curved.
• (b) The pan tiles are comparatively heavier, stronger and durable than curved tiles.
• (c) The fire bricks are generally used for lining kilns.
• (d) none of the above