1. Which of the following is not an ore of Aluminium ?
(A) Felsper
(B) Bauxite
(C) Cryolite
(D) Azurite
Ans : Azurite

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2. Most soluble in water is —
Ans : Sugar

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3. Bromine is —
Ans : A red liquid.

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4. The metal used in storage batteries —
Ans : Lead

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5. Water has maximum density at —
Ans : 4°C

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6. The chemial name of Uria is —
Ans : Carbamide

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7. Permanent hardness of water can be removed by adding —
Ans : Washing Soda

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8. The formula of Plaster of Paris is —
Ans : 2CaSO₄, H₂O

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9. Which of the following substance is a bad conductor of electricity but a good conductor of heat ?
Ans : Mica.

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10. Carborandum is —
Ans : Silicon Carbide

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11. Which of the following is the best conductor of electricity ?
Ans : Silver

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12. Washing soda is the common name of —
Ans : Sodium Carbonate

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13. The filament of electric bulb is made of —
Ans : Tungsten

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14. Bleaching powder is made from —
Ans : Lime and Chlorine

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15. The two elements that are frequently used for making transistors are —
Ans : Silicon and Germinium

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16. Which of the following gas is not known as green house gas ?
Ans : Nitrous oxide

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17. Which of the following is not a neutral oxide ?
(A) Carbon Monoxide
(B) Sulphur Dioxide
(C) Water
(D) Nitric Oxide
Ans : Sulphur Dioxide

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18. Which of the following is used in making smoke bombs ?
(A) Sulphur
(B) Phosphorus
(C) Hydrogen
(D) Carbon
Ans : Phosphorus 19. Caustic Soda is —
Ans : NaOH

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20. Chemical formula of Water glass is —
Ans : Na₂SiO₃

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21. Which of the following is not a bleaching agent ?
(A) Sulpher di-oxide
(B) Carbon di-oxide
(C) Sodium hypochlorite
(D) Chlorine
Ans : Carbon di-oxide

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22. The gas usually filled in electric bulb is —
Ans : Nitrogen

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23. Heavy water is —
Ans : Deuterium oxide

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24. The gases used in different types of welding would include —
Ans : Oxygen & acetylene

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25. Which of the following alloys is used for making magnets ?
(A) Duralumin
(B) Stainless Steel
(C) Alnico
(D) Magnelium
Ans : Alnico

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