Pick out the wrong statement.
A. Electrical conductivity of refractory is not important, when these are to be used in electrical furnaces
B. Graphite and metals are the good electrical conductor among the refractories and others are all electrical insulators
C. Refractories used for lining electrical furnaces should ordinarily have very low electrical conductivity
D. Electrical conductivity of porous refractory material is low
Answer: Option A
Fusion point of an acidic refractory material is
A. Increased by the addition of basic oxides
B. Reduced by the addition of basic oxides
C. Not affected by the addition of basic oxides
D. Not affected by the addition of basic oxides
Which of the following is not a high alumina refractory material?
A. Kyanite
B. Sillimanite
C. Diaspore
D. Periclase
Magnesite refractories are generally not used in the
A. Electric furnace walls
B. Steel melting furnace
C. Open hearth furnace
D. Burning zone of cement kilns
Join The Discussion