Consider the following statements:

a) Mechanical waves require a material medium for their propagation

b) Mechanical waves do not require a material medium for their propagation

c) In longitudinal waves, particles of the medium vibrate in the direction of wave motion

d) In longitudinal waves, particles of the medium vibrate perpendicular to the direction of wave motion

Which of the following statements are correct?

Question

Question

Answer 1

CONCEPT:

Waves:

A wave is a disturbance in a medium that carries energy without a net movement of particles.
Types of waves:
- On the basis of the necessity of medium:

Mechanical waves	Non-mechanical waves
Require medium for their propagation e.g. Waves on string and spring, waves on the water surface, sound waves, seismic waves.	Do not require a medium for their propagation are called e.g, Light, heat (Infrared), radio waves, γ- rays, X-rays, etc.

Transverse waves	Longitudinal waves
Particles of the medium vibrate in a direction perpendicular to the direction of propagation of the wave.	Particles of a medium vibrate in the direction of wave motion.

EXPLANATION:

Mechanical waves:

Require medium for their propagation e.g. Waves on string and spring, waves on the water surface, sound waves, seismic waves.

Transverse waves:

Particles of the medium vibrate in a direction perpendicular to the direction of propagation of the wave.
Therefore statement a and c are correct.
Hence, option 1 is correct.