Related Mcqs:

1. Faster rate of drying of moulded refractories results in high ______________ of refractories?

   A. Green strength
   B. Voids
   C. Shrinkage
   D. Both B. and C.

2. A metal oxide is reduced by heating it in a stream of hydrogen. After complete reduction, it is found that 3.15 gm of the oxide has yielded 1.05 gm of the metal. It may be inferred that the ____________________?

   A. Atomic weight of the metal is 4
   B. Equivalent weight of the metal is 4
   C. Atomic weight of the metal is 2
   D. Equivalent weight of the metal is 8

3. The boiling points for pure water and pure toluene are 100°C and 110.6°C respectively. Toluene and water are completely immiscible in each other. A well agitated equimolar mixture of toluene and water are prepared. The temperature at which the above mixture will exert a pressure of one standard atm. is___________________?

   A. Less than 100°C
   B. 100°C
   C. Between 100 and 110°C
   D. 110.6°C

4. 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

5. Refractories used in/for ______________ should have low thermal conductivity?

   A. Coke ovens
   B. Insulation
   C. Regenerators
   D. Muffle furnaces

6. Panel test determines the ______________ of refractories?

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

7. Presence of MgO in alumino-silicate refractories ______________ its refractoriness ?

   A. Increases
   B. Lowers
   C. Does not affect
   D. Either A. or B.; depends on its quantity

8. Hot metal runner in blast furnace are lined with ______________ bricks?

   A. Silica
   B. Carborundum
   C. Fireclay
   D. Magnesite

9. Roof of a basic electric furnace is made of ______________ bricks?

   A. Superduty fireclay
   B. Silica
   C. Chromite
   D. None of these

10. Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of ______________ °C?

    A. 770
    B. 570
    C. 270
    D. 70