```       (d) remains the same
Ans : (b)
326. A piece of paper and a cricket ball are dropped from the same height. Under which of the following conditions do both reach the
surface simultaneously? [CPO SI 2010]
(a) They must have the same volume
(b) They must have the same density
(c) They must have the same mass
(d) They must be dropped in vacuum
Ans : (d)
327. The frequency of ultrasound wave is typically [CPO SI 2010]
(a) Above 20 kHz
(b) Above 20,000 kHz
(c) Below 20 kHz
(d) Below 02 kHz
Ans : (b)
328. The function of heavy water in a-nuclear reactor is to [CSAT 2011]
(a) Slow down the speed of neutrons
(b) Increase the speed of neutrons
(c) Cool down the reactor
(d) Stop the nuclear reaction
Ans : (a)
329. An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth [CSAT2011]
(a) does not exist at such distance
(b) is neutralized by the attraction of the moon
(c) provides the necessary speed for its steady motion
(d) provides the necessary acceleration for Its motion
Ans : (d)
330. The surface of a lake is frozen in severe winter," but the water at its bottom is still liquid. What isthe reason? [CSAT 2011]
(a) Ice is a bad conductor of heat
(b) Since the surface of the lake is at the same temperature as the air, no heat is lost
(c) The density of water is maximum at 4°C
(d) None of the statements (a), (b) and (c) given above is correct
Ans : (c)
254
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