The linear thermal expansion of _______________ bricks upto 1000 °C is very low of the order of ≤ 0.5 percent?

Related Mcqs:

1. The maximum linear expansion of silica bricks during firing is about ______________ percent?

   A. 0.5
   B. 1
   C. 2
   D. 3.5

2. 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

3. Semi-silica bricks compared to silica bricks have_______________?

   A. Less fusion point
   B. Better spalling resistance
   C. Both A. and B.
   D. Neither A. not B.

4. Hot blast main (carrying air at 1000°C) in blast furnace are lined with ______________ bricks?

   A. Silica
   B. Fireclay
   C. Magnesite
   D. Zirconia

5. 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

6. Porosity of silica bricks varies from ______________ percent?

   A. 5 to 10
   B. 20 to 30
   C. 45 to 60
   D. 60 to 75

7. Maximum apparent porosity of magnesite bricks is about _____________ percent?

   A. 8
   B. 24
   C. 44
   D. 58

8. 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

9. 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.

10. Pure oxide refractories are generally monocrystalline in nature and are self bonded _______________ bricks are generally used as moderator in nuclear reactors?

    A. Beryllia
    B. Carborundum
    C. Corundum
    D. Thoria