Question

1.   Water is a ________
        a. Natural substance
        b. Man made substance
        c. Both of these
        d. None of these
2.   When coal burns in air then
        a. Carbon dioxide is formed
        b. Sulphur dioxide is formed
        c. Carbon monoxide is formed
        d. Hydrogen gas is formed
3.   Purest form of carbon is
        a. Coal
        b. Charcoal
        c. Coke
        d. All of these
4.   Coaltar contains about
        a. 300 substance
        b. 400 substance
        c. 200 substance
        d. 100 substance
5.   The first oil well was drilled in
        a. USA
        b. USSR
        c. UK
        d. India
6.   PCRA stands for
        a. Public Conservations Research Association
        b. Petroleum Conservation Research Association
        c. Public Council of Research Association
        d. Partial Counting of remaining Amendment
7.   An example of fossil fuel is
        a. Wood
        b. Animal waste
        c. Coal
        d. All of these
8. When magnesium ribbon burnt it produce
a. Magnesium hydroxide
b. Magnesium oxide
c. Magnesium chloride
d. Magnesium sulphate

9. Charcoal burns in air producing-
a. CO2
b. CO
c. H2
d.O2

10. Combustion is a reaction in which a Substance reacts with-
a. Hydrogen
b. Nitrogen
c. Oxygen
d. Chlorine

11. Fuel may be-
a. Solid
b. Liquid
c. Gas
d. All of these

12. Which one of the following is fuel of our body?
a. Petrol
b. Diesel
c. Food
d. Water

13. Combustion is a-
a. Physical process
b. Chemical process
c. Both (a) & (b)
d. None of these

14. Which one of the following is combustible?
a. Iron nail
b. Glass
c. Stone pieces
d. Paper

15. Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play
(a) only if the objects are solid.
(b) only if one of the two objects is liquid.
(c) only if one of the two objects is gaseous.
(d) irrespective of whether the objects are solid, liquid or gaseous.

16. To sharpen the blade of a knife by rubbing it against a surface, which of the following will be most suitable?
(a) stone
(b) plastic block
(c) wooden block
(d) glass block

17. In a large commercial complex there are four ways to reach the main road. One of the path has loose soil, the second is laid with polished marble, the third is laid with bricks and the fourth has gravel surface. It is raining heavily and Paheli wishes to reach the main road. The path on which she is least likely to slip is
(a) loose soil.
(b) polished marble.
(c) bricks.
(d) gravel.

18. A toy car released with the same initial speed will travel farthest on
(a) muddy surface
(b) polished marble surface
(c) cemented surface
(d) brick surface

19. Which of the following statements is incorrect?
(a) Friction acts on a ball rolling along the ground.
(b) Friction acts on a boat moving on water.
(c) Friction acts on a bicycle moving on a smooth road.
(d) Friction does not act on a ball moving through air.

20. If we apply oil on door hinges, the friction will
(a) increase
(b) decrease
(c) disappear altogether
(d) will remain unchanged
​

Answer 1

Answer:

1.natural substance

2.carbon dioxide

3.charcoal

4.200 substance 5.

Answer 2

Answer:

1. natural .

2 . carbon dioxide

3 . charcoal .

I only know three ..... Mark me as brainliest