Question

Which of the following is/are correct about sound (in air) and light wave?

• A. Sound is a longitudinal wave.
• B. Both can travel through the vacuum.
• C. Light is a transverse wave.
• D. Both of them are mechanical waves.

Answer 1

Answer: (A), (C)

The correct options are
A Sound is a longitudinal wave.
C Light is a transverse wave.

Sound waves in air are longitudinal waves because the wave motion of sound and the motion of the particles are in the same direction.

Sound is a mechanical wave as it requires a medium to propagate. So it cannot travel through the vacuum.

Light waves are transverse waves because the components of light i.e the magnetic and electric fields vibrate perpendicular to the direction of propagation. Since it can travel through vacuum, it is a non-mechanical wave.