High porosity refractory bricks have________________?

Related Mcqs:

1. 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...

2. Refractory bricks having lower porosity have _____________________?

   A. High insulating properties B. Low heat capacity C. Low thermal conductivity D. Greater strength...

3. 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....

4. 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...

5. Maximum alumina content in high alumina refractory can be as high as ____________ percent?

   A. 30 B. 50 C. 70 D. 90...

6. Thermal diffusivity of a refractory brick is high, when its ______________ is high?

   A. Density B. Specific heat C. Thermal conductivity D. None of these...

7. With increase in the porosity, thermal spalling resistance of fireclay brick_______________?

   A. Increases B. Decreases C. Remain same D. May increase or decrease...

8. Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called_________________?

   A. Spalling resistance B. Refractoriness C. Refractoriness under load (RUL) D. None of these...

9. Which is a neutral refractory ?

   A. Graphite B. Magnesite chrome C. Silica D. Magnesia...

10. Which is not an acidic refractory ?

    A. Silica B. Fireclay C. High alumina refractory D. Carbon black...