Faster rate of drying of moulded refractories results in high _____________ of refractories?

Related Mcqs:

1. Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as _____________ percent?

   A. 55
   B. 70
   C. 80
   D. 90

2. Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as ______________ percent?

   A. 10
   B. 15
   C. 20
   D. 30

3. Because of its very high refractoriness of the order of __________ °C, silicon carbide refractories are used in zinc smelting furnace, muffle furnace and for supporting the wares in tunnel kilns ?

   A. 1800
   B. 2200
   C. 2400
   D. 2700

4. Carbon refractories have very high __________________?

   A. Wetting characteristics
   B. Refractoriness
   C. Thermal conductivity
   D. Both B. and C.

5. High alumina refractories are used in the ___________________?

   A. Dome of blast furnace stoves
   B. Electric arc furnace roof
   C. Glass melting furnaces
   D. All A., B. and C.

6. Rate of slag attack on refractories increases with rise in temperature due to the___________________?

   A. Decreased viscosity of slag
   B. Increased thermal conductivity of brick
   C. Oxidising condition in the furnace
   D. None of these

7. Machine moulding of dry mixture of refractories requires a pressure of the order of _____________ kg/cm2?

   A. 10
   B. 100
   C. 500
   D. 1000

8. Except _____________, all other refractories are bad conductors of electricity (i.e, have low electrical conductivity)?

   A. Fireclay
   B. Carborundum
   C. Graphite
   D. Chromite

9. Panel test determines the _____________ of refractories?

   A. Fusion point
   B. Spalling resistance
   C. Slag penetration resistance
   D. Refractoriness under load (RUL)

10. Spray test determines the _____________ of refractories?

    A. Resistance to slag penetration
    B. Resistance to CO attack
    C. RUL
    D. Permanent linear change