When mechanical waves have a frequency below the audible range, they are called :

Which waves are used in sonography?

The sound carried by air from a sitar to a listener is a wave of the following type :

Sound waves do not show in air :

With the rise of temperature, the velocity of sound:

Velocity of sound will be :

The velocity of sound is largest in :

Supersonic planes fly :

Resonance is an example of:

Buzzing of a mosquito is :

Quality of sound depends upon its :

Pitch of sound depends upon it;

Decibel is:

The law applicable for determining the apparent change in frequency when a source and an observer are in motion is :

Doppler’s effect of sound is produced when the source and the observer are :

The Doppler effect is applicable for :

To a stationary man the frequency of a sound source moving towards the man appears to be :

The main cause of difference between Doppler effect in sound and light is :

When a sound source is in motion and observer is at rest then the cause of apparent change in frequency is :

Which of the following is not the use of Doppler effect?

Which quantity remains constant in the phenomenon of refraction?

The absolute refractive index is maximum for:

The inference derived from the refraction of light is that:

The Plank’s Quantum theory was experimentally verified by :

As a result of hole in the ozone belt: