A. High insulating properties
B. Low heat capacity
C. Low thermal conductivity
D. Greater strength
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 - 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. - Refractory bricks with lower permeability is produced by using _________________?
A. Higher firing temperature
B. Higher moulding pressure
C. Finer grog size
D. All A., B. and C. - Water content in ground refractory material to be shaped into bricks by hand moulding is about _____________ percent?
A. 5
B. 20
C. 40
D. 55 - Lower wall courses of soaking pits are made of _____________ bricks to avoid the action of molten slag & scale?
A. Chrome or magnesite
B. Silicon carbide
C. Silica
D. Low duty fireclay - Isotopes are atoms having the same _____________________?
A. Mass number
B. Number of neutrons
C. Atomic mass
D. None of these - With increase in the porosity, thermal spalling resistance of fireclay brick_______________?
A. Increases
B. Decreases
C. Remain same
D. May increase or decrease - A solution having a pH value of 5 is less acidic than the one having a pH value of 2 by a factor of ________________?
A. 3
B. 100
C. 1000
D. None of these - Thermal conductivity of refractory bricks____________________?
A. Increases with decrease in porosity
B. Decreases with decreases in porosity
C. Is independent of its porosity and is maximum for insulating bricks
D. Increases with the amount of air entrapped in pores - Maximum alumina content in high alumina refractory can be as high as ____________ percent?
A. 30
B. 50
C. 70
D. 90
