(d) none of these
Ans: (c)
54.The scientist associated with floatation is: [RRB CC 2005]
   (a) Archemedes
   (b) Newton
   (c) Louis Pasteur
   (d) All of these
Ans: (a)
55.Satellites used for tele-communication relay are kept in a geostationary orbit.
   A satellite is said to be in such an orbit when: [CSAT (Pre) 2011]
   1) The orbit is geosynchronous
   2) The orbit is circular
   3) The orbit lies in the plane of the earth"s equator
   4) The orbit is at an altitude of 22,236km
   Select the correct answer using the codes given below:
   (a) 1, 2 and 3 only
   (b) 1, 3 and 4 only
   (c) 2 and 4 only
   (d) 1, 2, 3 and 4 all
Ans: (a)
56.If a coin is tossed upwards from the ground with a velocity of 9.8m/ sec then
   it rises to a height: [BPSC (Pre) 2008]
   (a) 9.8 m
   (b) 10 m
   (c) 4.9 m
   (d) 49 m
Ans: (c)
57.The frequency of sound waves in the audible range is : [RRB ASM/CC
   (a) 20 Hz - 20,000 Hz
   (b) 0.5 Hz - 5 Hz
   (c) 1 Hz - 10 Hz