(b) will decrease
   (c) will be same
   (d) will firstly increase then it would decrease
Ans: (c)
31.Due to contraction of eyeball, a long sighted eye can see only: [CDS, 2011]
   (a) farther objects which is corrected by using convex lens
   (b) farther objects which is corrected by using concave lens
   (c) nearer objects which is corrected by using convex lens
   (d) nearer objects which is corrected by using concave lens
Ans: (c)
32.Why do you feel cool under a tree but not so under a tin shed on a sunny
   day? [CDS 2011]
   (a) The greenness of the tree gives the cool feeling
   (b) Photosynthesis absorbs heat
   (c) The leaves convert water vapours into water which is a heat absorbing
       process
   (d) The leaves give out water which vaporizes absorbing some heat as latent
       heat
Ans: (d)
33.Why an iron nail floats on mercury but sinks in water? [UPSC (Pre) 1994]
   (a) less chemical affinity of iron than mercury with water
   (b) the weight of iron nail is more than water but less than mercury
   (c) the density of iron is more than water but less than mercury
   (d) None of these
Ans: (c)
34.Water has its maximum density at: [BPSC (Pre) 1998]
   (a) 100°C
   (b) 4°C
   (c) 0°C
   (d) - 4°C
Ans: (b)
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