(a)   remain constant in both pitch and loudness
       (b)   stay constant in pitch but decrease in loudness
       (c)   increase in frequency and intensity
       (d)   decrease in frequency and intensity
Ans : (d)
198. To an astronaut, outer space appears:
       (a) white
       (b) black
       (c) deep blue
       (d) crimson
Ans : (b)
199. The working of optical fibres is based on the of electromagnetic waves.
       (a) refraction
       (b) reflection
       (c) total internal reflection
       (d) polarization
Ans : (c)
200. A body is stable if it has a :
       (a) broad base and a high centre of gravity
       (b) broad base and a low centre of gravity
       (c) narrow base and a high centre of gravity
       (d) narrow base and a low centre of gravity
Ans : (b)
201. If a body starts its motion from a point and comes back to its initial position after a certain time then since:
       (a) its displacement is zero, average velocity is zero
       (b) its displacement is zero average speed is zero
       (c) total distance travelled is not zero, average speed is zero
       (d) total distance travelled is zero, average velocity is not zero
Ans : (a)
202. A wave in which the particles of the material move up and down as the wave goes from left to right is known as :
       (a) longitudinal
       (b) transverse
       (c) sound
       (d) compressional
Ans : (b)
203. What should be done to increase the pitch of a string instrument?
          I.     Increase the length of the string used.
         II.     Decrease the guage of the string used.
        III.     Loosen the string.
        IV.      Tighten the string.
       (a) I and IV
       (b) II and IV
       (c) I, II and IV
       (d) I and III
Ans : (b)
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