Question

Sound waves in air are ________ waves.
A. Longitudinal
B. Radio
C. Transverse
D. Electromagnetic

Answer 1

Hint: Learn about wave and vibration. Study the propagation of sound waves and the concept behind it. Then try to understand the propagation of the longitudinal, transverse, radio and electromagnetic waves and their properties. Compare the properties with sound waves and we will get our answer.

Complete Step-by-Step solution:
Sound waves are produced from the vibrations of a vibrating object. When a body vibrates its vibrations propagates through the medium by compression and expansion of the medium to the observer or the listener.
Longitudinal waves can be defined as the wave where the particles in the medium where the wave is propagating move parallel to or in the direction of the wave.
A transverse wave can be defined as a wave where the particles in the medium where the wave is propagating moves in the perpendicular direction of the wave.
Radio wave is an electromagnetic wave which has both electric and magnetic components in a perpendicular direction.
Electromagnetic waves have both the electric field and magnetic field components in perpendicular direction to each other.
Now, if we consider the sound wave it propagates as the particles in the medium are compressed and expanded by the vibration in the direction of propagation of the vibration. The concept is similar to the propagation of the longitudinal wave. So, we can say that the sound wave propagates as a longitudinal wave.
The correct option is (A).

Note: Since when a transverse wave is propagating through a medium the particles move in perpendicular direction, the sound wave is not a transverse wave.
Electromagnetic waves can also propagate in vacuum which is not possible for sound waves. We need a medium for propagation of sound waves. So, we can say that sound waves are not electromagnetic waves.
Again, radio waves are also a part of the electromagnetic spectrum. It can also travel in vacuum which is not possible for sound waves.