1. Refractories are used in
(A) Furnaces
(B) Machines
(C) Electric motors
(D) Automobiles
2. Refractories keep their------------ at high temperatures.
(A) Acidity
(B) Basicity
(C) Neutrality
(D) Strength
3. In Silica Bricks binding material is
(A) MgO
(B) CaO
(C) CdO
(D) BaO
4. The percentage of SiO2 in Fire Clay Bricks is
(A) 40
(B) 70
(C) 60
(D) 50
5. Corundum Refractories contain
(A) Al2O3
(B) Bi2O3
(C) Fe2O3
(D) Sb2O3
6. High Alumina Bricks are mostly used in
(A) Rotary Kiln
(B) Tank furnace of glass
(C) Coke oven
(D) Blast furnace
7. Carborundum Refractories contain
(A) Zinc carbide
(B) Silicon carbide
(C) Sodium carbide
(D) Calcium carbide
8. Fusion temperature of super refractory in centigrade is more than
(A) 500
(B) 2000
(C) 1500
(D) 1000
9. Zirconia bricks are-------------- Refractories.
(A) Acidic
(B) Basic
(C) Normal
(D) Neutral
10. Magnisite bricks are-------------- Refractories.
(A) Acidic
(B) Normal
(C) Neutral
(D) Basic
11. Dolomite bricks are-------------- Refractories.
(A) Acidic
(B) Basic
(C) Neutral
(D) Normal
12. The most popular scale of abrasive hardness is
(A) Vickers’
(B) Knoops’
(C) Johns’
(D) Mohs'
13. Abrasives are important since all-------------- require it.
(A) Industries
(B) Schools
(C) Hospitals
(D) Shops
14. Which one is both a natural and man-made synthetic abrasive.
(A) Silicon carbide
(B) Norbide
(C) Corundum
(D) Diamond
15. Which one is natural abrasive.
(A) Cubic boron nitride
(B) Corundum
(C) Norbide
(D) Silicon carbide
16. Which one is artificial (Synthetic) abrasive.
(A) Norbide
(B) Emery
(C) Corundum
(D) Garnet
17. In emery the percentage of corundum is about
(A) 40
(B) 50
(C) 60
(D) 69
18. The hardness of Silicon Carbide in MOHS’ scale is
(A) 6.5
(B) 7.5
(C) 9.5
(D) 8.5
19. Which one is present in abrasive crocus.
(A) Zinc oxide
(B) Aluminium oxide
(C) Iron oxide
(D) Calcium oxide
20. Which abrasive is chemically carbon
(A) Silicon carbide
(B) Norbide
(C) Corundum
(D) Diamond