1641: Which one of the following is the appropriate reason for considering the Gondwana rocks as most important of rock systems of India?
(a) More than 90% of limestone reserves of India are found in them
(b) More than 90% of India's coal reserves are found in them
(c) More than 90% of fertile black cotton soils are spread over them
(d) None of the reasons given above is appropriate in this context
1642: What is the difference between the antelopes Oryx and Chiru?
(a) Oryx is adapted to live in hot and arid areas whereas Chiru is adapted to live in steppes and semi-desert areas of cold high mountains
(b) Oryx is poached for its antlers whereas Chiru is poached for its musk
(c) Oryx exists in western India only whereas Chiru exists in north-east India only
(d) None of the statements (a), (b) and (c) given above is correct
1643: In a remote Indian village with a scarcity of fuel, the people draw water from a well. They should be advised before drinking that water to:
(a) Boil it
(b) Use ion exchange resins
(c) Use solar stills for distilling
(d) Use potassium permanganate for purifying the water
1644: The sun derives its energy from:
(a) Nuclear fission reactions.
(b) Nuclear fusion reactions.
(c) Oxidation of helium.
(d) Fission of noble metals.
1645: Assertion (A)
Lal, Bal and Pal formed extremist group in the Indian National Congress
Reason (R)
They were revolutionary leaders
(a) A and R both are incorrect
(b) A is correct but R is incorrect
(c) A and R are correct and R is the correct explanation of A
(d) A and R are correct but R is not the correct explanation of A