Chapter 13: Sound

1.A list of mediums is given below.
(i)wood  (iii)air
(ii)water (iv)vacuum
In which of these mediums can sound travel?
(a)i & ii only   (b)i, ii & iii only        (c)iii & iv only
(d)ii, iii & iv only
2.The loudness of sound depends on:
(a)its amplitude.       
(b)its frequency. (c)its time period.  (d)its speed.
3.Which of the following statements are correct?
(i)Sound is produced by vibrations.
(ii)Sound requires a medium for propagation.
(iii)Light and sound both require a medium for propagation.
(iv)Sound travels slower than light.
(a)i & ii only
(b)i, ii & iii only
(c)ii, iii & iv only
(d)i, ii & iv only