115. A permanent magnet repels: [CDS 2001)
     (a) ferromagnetic substances only
     (b) diamagnetic substances only
     (c) paramagnetic substances only
     (d) body paramagnetic and diamagnetic substances
Ans : (b)
116. The specific resistance of conducting wire depends upon [NDA 2010]
     (a) length of the wire, area of cross-section of the wire and material of the wire
     (b) length of the wire and area of, cross-section of the wire but not on the material of the wire
     (c) material of the wire only but neither on the length of the wire nor on the area of cross-section of the wire
     (d) length of the wire only but neither on the area of cross-section of the wire nor on the material of the wire
Ans : (a)
117. Match the following:
         Types of Waves                  Their Application
     A.    Matter Waves              1.    Surgery using
                                           Lasers
     B.    Electromagnetic           2. Acoustic Radar
           Waves
     C.    Elastic Waves             3.    Electron
                                           Microscope
     D.    Longitudinal Waves        4.    Musical instrument
            A        B          C          D
       (a)  3        1          4          2
       (b)  1        3          4          2
       (c)  3        1          2          4
       (d)  1        3          2          4
Ans : (c)
118. The chance of vehicle to overturn whole negotiating a circular path depends on : [CDS 2002]
       (a) speed of the vehicle only
       (b) radius of the circular path only
       (c) speed and height of the vehicle; and radius of the circular path
       (d) height of the vehicle only
Ans : (c)
119. A fan produces a feeling of comfort during hot weather, because [NDA 2010]
       (a) our body radiates more heat in air
       (b) fan supplied cool air
       (c) conductivity of air increases
       (d) our perspiration evaporates rapidly
Ans : (d)
120. The difference between a nuclear reactor and an atomic bomb is that: [IAS 1995]
       (a) no chain reaction takes place in nuclear reactor while in the atomic bomb there is a chain reaction
       (b) no chain reaction takes place in atomic bomb while it takes place in nuclear reactor
       (c) the chain reaction in nuclear reactor is controlled
       (d) the chain reaction in nuclear reactor is not controlled
Ans : (c)
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