A. Composite material containing both ceramic & metallic constituents
B. Having high strength & resistance to high temperature
C. Used in space vehicles, missiles & nuclear energy plants
D. All A., B. and C.
Related Mcqs:
- Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the_______________?
A. Hearth of the blast furnace
B. Nuclear reactors, missiles & space crafts
C. Insulation of high temperature furnaces
D. Roof of electric furnaces - Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of ______________ percent respectively?
A. 80 and 20
B. 20 and 80
C. 50 and 50
D. 60 and 40 - 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 - Carbon refractories are exclusively used in the_________________?
A. Hearth of blast furnace
B. Walls of coke oven
C. Regenerators of coke oven
D. Side wall of soaking pits - Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material ?
A. Aluminium phosphate
B. Water
C. Lime
D. Plaster of Paris - Except _____________, all other refractories are bad conductors of electricity (i.e, have low electrical conductivity)?
A. Fireclay
B. Carborundum
C. Graphite
D. Chromite - Thermal diffusivity of a refractory brick is high, when its ____________ is high?
A. Density
B. Specific heat
C. Thermal conductivity
D. None of these - Sillimanite (Al2O3.SiO2) refractory, which is a neutral refractory, is not used in________________?
A. Pottery furnace
B. Glass melting furnace
C. Crucibles
D. Gas retorts - With increasing alumina content, the fusion point of high alumina refractories__________________?
A. Increases
B. Decreases
C. Remain constant
D. May increase or decrease; depends on its alumina content - Addition of zircon to silica refractory brick improves its_____________________?
A. Crushing strength
B. Resistance to slag attack
C. Both A. and B.
D. Neither A. nor B.
