A. 30
B. 50
C. 70
D. 90
Stoichiometry
Stoichiometry
A. 5
B. 20
C. 40
D. 55
A. Cost
B. Electrical conductivity
C. Thermal conductivity
D. Fusion point
A. Higher firing temperature
B. Higher moulding pressure
C. Finer grog size
D. All A., B. and C.
A. Thermal spalling
B. Slag attack
C. Fusion under load
D. CO attack
A. Crushing strength
B. Resistance to slag attack
C. Both A. and B.
D. Neither A. nor B.
A. Atomic heat capacities of the crystalline solid elements are nearly constant and equal to 6.2 kcal/kg-atom according to the law of Petit and Dulong
B. Atomic heat capacities of all solid elements decrease greatly with decrease in temperature, approaching a value of zero at absolute zero temperature, when in the crystalline state
C. Generally, the heat capacities of compounds are lower in the liquid than in the solid state
D. The heat capacity of a heterogeneous mixture is an additive property, but when solutions are formed, this additive property may no longer exist
A. 1 BTU =453.6 calories
B. 1 BTU = 252 calories
C. 1 calorie = 252 BTU
D. 1 calorie = 453.6 BTU
A. Insulating refractories used in place of regular refractory bricks are usually called light weight refractories, and they have similar composition as heavy bricks
B. Graphite refractories are also called plumbago refractories
C. Superduty fireclay bricks correspond to a pyrometric cone equivalent of 26-28
D. Calcined magnesite is also called dead burnt magnesite
A. Refractories used in muffle furnace should have low thermal conductivity
B. The electrical resistivity of refractories drops rapidly with rise in temperature
C. For reducing spalling tendency, the refractory should be well fired and its porosity should be more
D. Refractoriness under load (RUL) of a refractory is always less than its refractoriness
