21: Assertion (A) :
The frequency of floods in North Indian plains has increased during the last couple of decades.
Reason (R) :
There has been reduction in the depth of river valleys due to deposition of silt.
(a) Both A and R are true, and R is the correct explanation of A
(b) Both A and R are true, but R is not a correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true
22: Consider the following climatic conditions (northern hemisphere) :
Temperature degree C - Rainfall Cm.
J 3.9 4.7
F 4.4 5.7
M 8.3 8.2
A 14.4 9.2
M 20.0 9.2
J 23.3 17.7
J 27.8 14.5
A 27.8 14.0
S 22.3 12.7
O 18.3 7.0
N 12.2 5.0
D 6.7 3.5
These are most likely to be found in the natural regions of
(a) China type
(b) Equatorial type
(c) Hot desert type
(d) Monsoon type
Explanation:
This is most likely to be found in the natural region of China type : which is typified by a warm moist summer and a cool, dry winter. Temperatures strongly modified by maritime influence.
23: Which one of the following is the continent with the highest mean elevation in the world ?
(a) Antarctica
(b) North America
(c) Asia
(d) South America
Explanation:
Antarctica is having highest mean elevation. It is located in South pole region. Its Eastern side is more elevated than the Western side.
24: Which of the following are some important pollutants released by steel industry in India?
1. Oxides of sulphur
2. Oxides of nitrogen
3. Carbon monoxide
4. Carbon dioxide
Select the correct answer using the code given below.
(a) 1, 3 and 4 only
(b) 2 and 3 only
(c) 1 and 4 only
(d) 1, 2, 3 and 4
25: Which one of the following countries is the leading producer of uranium?
(a) United States of America
(b) Zambia
(c) Canada
(d) Germany
Explanation:
Canada is the leading producer of Uranium in the world mainly from the deposits situated in Saskatchewan. Australia has the largest reserve of Uranium followed by S. Africa and Nigeria.