5 The coefficient of thermal expansion of refractory material should be
a) Very high
b) High
c) Medium
d) Low
6 Alumina is a…… type of refractory
a) Acid
b) Neutral
c) Basic
d) None of the above
7 Regenerators are widely used in
a) Reheating furnaces
b) Heat treatment furnaces
c) Baking ovens
d) Glass melting furnaces
8 Heat loss through openings in furnaces is directly proportional to
a) Fourth power of absolute temperature
b) Square of absolute temperature
c) Absolute temperature
d) ourth power of temperature
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