Question

State three conditions necessary for the formation of an echo.

Answer 1

Conditions for Hearing the Echo

1. The time interval between the source sound and the reflected sound must be at least 0.1 seconds.
2. The minimum distance between the obstacle (reflector) and the source of sound should be around 17 m (for air).
3. The size of the reflector should be comparable to the wavelength of the sound.
4. Intensity of sound should be sufficient to be audible.