A. Increases
B. Decreases
C. Remain same
D. May increase or decrease
Related Mcqs:
- An insulating refractory brick should have high porosity and low thermal conductivity. Which of the following is not used for inducing porosity in the insulating refractory bricks during its manufacture ?
A. Cork
B. Saw dust
C. Sand
D. Chemically prepared foam - In panel test for spalling resistance, the average face temperature of panel assembly is maintained at _____________ °C for 24 hours?
A. 700
B. 1000
C. 1600
D. 2000 - 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 - Fireclay refractories___________________?
A. Are not resistant to the action of basic slags
B. Combine with salts (e.g. chlorides sulphates etc.) & bases (e.g. lime, magnesia etc.) forming
fusible aluminates silicates etc
C. Shrink during firing
D. All A., B. and C. - Fireclay bricks is not used for lining the_______________?
A. Cupola
B. Gas producer
C. Bottom of hot metal mixer
D. Roof of open hearth furnace - Fireclay bricks are not used in the_________________?
A. Blast furnace
B. Hot blast stove
C. Cupola
D. Wall of coke oven - Fireclay bricks are not used in the________________?
A. Beehive coke oven
B. By-product coke oven walls
C. Combustion chamber of B.F. stoves
D. Coke oven regenerators - Fireclay bricks are used in the______________?
A. Coke ovens regenerator
B. Outer lining of L.D. converter
C. Hearth bottom of blast furnace
D. Coke oven walls - Refractory bricks having lower porosity have _____________________?
A. High insulating properties
B. Low heat capacity
C. Low thermal conductivity
D. Greater strength - High porosity refractory bricks have________________?
A. Poor resistance to the penetration of molten slag, metal & flue gases
B. Poor heat conductivity & low strength
C. Better thermal spalling resistance
D. All A., B. and C.
