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