76) The natural drying of bricks is also called hack drying.

• (a) True
• (b) False

77) The indentation marks left on bricks during the process of moulding, are known as

• (a) fillets
• (b) frogs
• (c) projections
• (d) marks

78) The frog of a brick is normally made on its

• (a) longer face
• (b) shorter face
• (c) bottom face
• (d) top face

79) The average out-turn of first class bricks in clamp burning is about

• (a) 50%
• (b) 60%
• (c) 70%
• (d) 80%

80) The average out-turn of first class bricks in kiln burning is

• (a) 50 to 60%
• (b) 60 to 70%
• (c) 70 to 80%
• (d) 80 to 90%