Related Questions

To resist spalling tendency, a refractory should have
A Greater diffusivity
B Low specific heat
C Low thermal co-efficient of expansion
D All of the above
Faster rate of drying of moulded refractories results in high __________ of refractories.
A Green strength
B Voids
C Shrinkage
D Both B and C
Spalling of a refractory means its
A Softening
B Fracture due to uneven expansion at high temperature
C Resistancce to compressive loads
D Resistance to chemical action of gases and molten fluxes
With increasing alumina content, the fusion point of high alumina refractories
A Increases
B Decreases
C Remains constant
D May increase or decrease ; depends on its alumina content
Spalling hammer is used for
A Driving wooden headed chisels
B Rough dressing of stones
C Carving of stones
D Breaking small projection of stones
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
Spalling resistance of a refractory can not be increased by
A Increasing its porosity
B Using a coarser grog during its manufacture
C Decreasing its thermal co-efficient of expansion
D Making it denser
Thermal spalling mainly occurs during __________ of furnaces.
A Cooling down
B Warming up
C Both A & B
D Neither A nor B
With increase in the porosity, thermal spalling resistance of fireclay brick
A increases
B decreases
C remains same
D may increase or decrease
Increasing the original price of an item by 15 percent and then increasing the new price by another 15 percent is equivalent to increasing the original price by
A 32.25%
B 31.00%
C 30.25%
D 35.54%

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