601: Which of the following periods can be considered as the era of mass revolution?
(a) 1856-1885 A.D.
(b) 1757-1857 A.D.
(c) 1920-1947 A.D.
(d) 1901-1919 A.D.
602: Consider the following :
1. Bats
2. Bears
3. Rodents
The phenomenon of hibernation can be observed in which of the above kinds of animals?
(a) 1 and 2 only
(b) 2 only
(c) 1, 2 and 3
(d) Hibernation cannot be observed in any of the above.
603: 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
604: When light enters a closed room through a small hole in the door, the image of an outside building appears as inverted on the opposite wall. This is because:
(a) The hole acts as a convex lens
(b) Light takes curvature at the edges of the hole
(c) Of rectilinear propagation of light
(d) The hole acts as a concave lens
605: A bag contains 20 balls, 8 balls are green, 7 are white and 5 are red. What is the minimum number of balls that must be picked up from the bag blind folded (without replacing any of it) to be assured of picking at least one ball of each colour ?
(a) 4
(b) 7
(c) 11
(d) 16