81.The dew doesn"t form in fast wind blowing during the night because: [BPSC
   1995]
   (a) the rate of vaporisation is fast
   (b) there is a lack of moisture in the wind
   (c) the temperature remains high
   (d) the sky is not clear
Ans: (a)
82.The main power supply in India is 220V, whereas that in the US is at 110V.
   Which one among the following statements in this regard is correct [NDA
   2012]
   (a) 110V is safer but more expensive to maintain
   (b) 110V is safer and cheaper to maintain
   (c) 110V leads to lower power loss
   (d) 110V works better at higher latitudes
Ans: (d)
83.For a steel boat floating on a lake, the weight of the water displaced by the
   boat is? [NDA 2012]
   (a) less than the weight of the boat
   (b) more than the weight of the boat
   (c) equal to the weight of the part of the boat which is below the water level
       of the lake
   (d) equal to the weight of the boat
Ans: (c)
84.The torque on a rectangular coil placed in a uniform magnetic field is large
   when the -[NDA 2012]
   (a) number of turns is large
   (b) number of turns is less
   (c) plane of the coil is perpendicular to the magnetic field
   (d) area of the coil is small
Ans: (a)
85.Two metallic wires A and B are of same material and have equal length. If
   the cross-sectional area of B is double that of A, then which one among the
   following is the electrical resistance of B? [NDA 2012]
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