(a)  1, 2 and 3
          (b)  1 only
          (c)  2 and 3
          (d)  1 and 2
Ans : (b)
255. If small raindrop falls through air [CDS 2009]
           (a) its velocity goes on increasing
           (b) its velocity goes on decreasing
           (c) its velocity goes on increasing for some time and then becomes constant
           (d) it falls with constant speed for some time and then its velocity increases
Ans : (c)
256. Television signal cannot be received generally beyond a particular distance due to [CDS 2009]
       (a) curvature of the earth
       (b) weakness of antenna
       (c) weakness of signal
       (d) absorption of signal In air
Ans : (a)
257. A person is Sitting In a car which is at rest. The reaction from the road at each of the four wheels of the car is R. When the car runs
     on a straight level road, how will the reaction at either of the front wheels vary? [IAS 2008]
        (a) It will be great r than R
        (b) It will be less than R
        (c) It will be equal to R
        (d) It shall depend on the material of the road
Ans : (c)
258. What is the correct sequence in which the lengths of the following units increase?
                1) Angstrom
                2) Micron
                3) Nanometer
           Select the correct answer using the codes given below [NDA 2008]
          (a)  1-2-3
          (b)  3-1-2
          (c)  1- 3 - 2
          (d)  2-3–1
Ans : (c)
259. Which one of the following is the unit of activity of a radioactive source? [NDA 2008]
           (a) Lux
           (b) Becquerel
           (c) Tesla
           (d) Siemens
Ans : (b)
260. A pendulum clock is set to give correct time at the sea level. The dock is moved to a hill station at an altitude above sea level. In
     order to keep correct time on the hill station which one of the following adjustments is required? [NDA 2008]
           (a) The length of the pendulum has to be reduced
           (b) The length of the pendulum has to be increased