With increase in the porosity, thermal spalling resistance of fireclay brick___________________?

Related Mcqs:

1. Porosity of fireclay refractories is _______________ percent?

   A. 5-10 B. 10-25 C. 25-35 D. 35-50...

2. Thermal spalling mainly occurs during _____________ of furnaces?

   A. Cooling down B. Warming up C. Both A. & B. D. Neither A. nor B....

3. Spalling resistance of a refractory cannot 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...

4. Silica bricks have low spalling resistance below 600°C, due to its________________?

   A. Very high thermal conductivity B. High co-efficient of expansion upto this temperature C. High thermal diffusivity D. Low refractoriness...

5. 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...

6. 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...

7. Spalling of a refractory means its____________________?

   A. Softening B. Fracture due to uneven expansion at high temperature C. Resistance to compressive loads D. Resistance to chemical action of gases and molten fluxes...

8. To resist spalling tendency, a refractory should have________________?

   A. Greater diffusivity B. Low specific heat C. Low thermal co-efficient of expansion D. All A., B. and C....

9. Spalling tendency of refractories is reduced by increasing its_________________?

   A. Porosity B. Specific gravity C. Thermal conductivity D. Strength...

10. Cold crushing strength of fireclay bricks is about ______________ kgf/cm2?

    A. 50-100 B. 100-150 C. 200-400 D. 500-1000...