Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of______________?

Related Mcqs:

1. _____________ is not a single oxide-refractory?

   A. Zirconia B. Silicon carbide C. Magnesia D. None of these...

2. Highest melting (m.p = 3070°C) oxide refractory is__________________?

   A. Alumina B. Thoria C. Zirconia D. Magnesia...

3. 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...

4. 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...

5. Beryllia (which is used in making crucibles for melting uranium & thorium) is superior to alumina in all respects for high temperature (> 1900°C ) use, except ?

   A. Cost B. Electrical conductivity C. Thermal conductivity D. Fusion point...

6. Fusion point of an acidic refractory material is________________?

   A. Increased by the addition of basic oxides B. Reduced by the addition of basic oxides C. Not affected by the addition of basic oxides D. Always more than 2500°C...

7. Mixing of ground refractory material and water is done in a ______________ mill?

   A. Pug B. Ball C. Tube D. Rod...

8. 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...

9. Which of the following is not a high alumina refractory material ?

   A. Kyanite B. Sillimanite C. Diaspore D. Periclase...

10. Fusion point of a basic refractory material is__________________?

    A. Reduced by the addition of acid oxides B. Increased by the addition of acid oxides C. Not affected by the addition of acid oxides D. Always less than 1000°C...