Question

The Doppler's effect is applicable for​

Answer 1

The Doppler's effect is applicable for​  electromagnetic waves

Answer 2

Answer:

An apparent change in the frequency of waves, as of sound or light, occurring when the source and observer are in motion relative to each other, with the frequency increasing when the source and observer approach each other and decreasing when they move apart.

Hence, it is applicable for both sound and light waves.