Answer :- Vulcanization
2. Which of the following gives the percentage of Carbon dioxide present in the atmosphere?
(5%; 3%; 0.3%; 0.03%)
Answer :- 0.03%
3. Which of the following is a group III metal?
(Calcium, Aluminium, Sodium, Iron)
Answer :- Aluminium
4. Temporary Hardness of water is due to?
Answer :- magnesium biarbonate
5. Which metal is separated through 'Dow Process'?
Answer :- Magnesium
6. Accidity in milk is caused by ?
7. DDT, the powerful insecticide contains the halogen?
Answer :- Chlorine
8. Sodium is kept in?
Answer :- Kerosene
9. Which is the heaviest metal?
Answer :- Osmium
10. Galvanized iron is coated with a thin coating of?
Answer :- Zinc
11. Which amoung the following inert gas is not presented in our atmosphere?
Answer :- Radon
12. The laws of electrolysis was discovered by?
Answer :- Faraday
13. Venturimeter is used for measuring?
Answer :- Flow of liquids
14. Half Life of Radio carbon is?
Answer :- 5730 years
15. Electron always flow from?
16. Dynamo works on the principle of?
Answer :- Electro magnetic induction
17. Impure water boils at temperature?
Answer :- above 100 degree centigrade
18. Which is known as 'Rock Cotton'?
Answer :- Asbestos
19. Which ray is used for taking photographs of inner organs of body?
Answer :- Hard X-ray
20. The body which absorbs all radiation incident upon it is called as?
Answer :- Black body