Question & Answer

Velocity of sound is maximum in-
  (a){\text{ Water}} \\
  (b){\text{ Oil}} \\
  (c){\text{ Air}} \\
  (d){\text{ Iron}} \\

ANSWER Verified Verified
Hint – The speed of sound depends upon the elasticity and density of the medium through which it is travelling, use this fact to figure out the right option.

Complete step-by-step answer:
In common everyday speech, speed of sound refers to the speed of sound waves in air. However, the speed of sound varies from substance to substance: typically sound travels most slowly in gases; it travels faster in liquids; and faster still in solids.
The speed of sound in dry air at 20 0C is 343 meters per second.
The speed of sound in water is 1480 meters per second.
The speed of sound in aluminium is 6320 meters per second.
Hence the speed of sound is greater in solids.
So among the following options only iron is a solid medium.
Hence option (D) is correct.

Note – The speed of sound is important because it is a measure of the shortest time in which a pressure change can be transmitted from one place to another. Speed of sound is also defined as the speed at which the smallest disturbance travels through a medium.