The surface of earth is surrounded by a thick layer of air (Gases), which reaches a height about ……….km.
a) 150
b) 200
c) 300
d) 400
Which of the following is used as a fuel in space shuttle?
a) liquid oxygen
b) carbon dioxide
c) liquid nitrogen
d) all of these
Carbon dioxide gas used in………
a) fire extinguishers b) soft drinks
c) the preparation of baking and washing soda
d) all of the above
The amount of argon gas is ………..in air.
a) 0.2 %
b) 0.3 %
c) 0.6 %
d) 0.9 %
Which of the following gas filled in the electric light bulbs?
a) CO2
b) Oxygen
c) Argon
d) Helium
Potassium nitrate is used as…
NTS PST 24/11/2019 (2:30)
a) Fertilizer
b) baking soda
c) sugar industry
d) disinfectant
