The correct statement is :
(a) Sound and light both require medium for propagation
(b) Sound can travel in vacuum, but light can not
(c) Sound needs medium, but light does not need medium for its propagation
(d) Sound and light both can travel in vacuum.
Complete the following sentences :
(a) Sound can not travel through ___, but it requires a ___ .
(b) When sound travels in a medium, the particles of medium ___ but the disturbance ___ .
(c) A longitudinal wave is composed of compression and ___ .
(d) A transverse wave is composed of crest and ___ .
(e) Wave velocity = ___ x wavelength.