An observer moves towards a stationary source of sound with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency?

An observer is moving towards the stationary source of sound, then

If an observer moves towards a stationary source of sound with a velocity of one tenth the velocity of sound, then the apparent increase in frequency will be

When an observer moves away from a stationary source of sound, the apparent pitch will

An observer is approaching a stationary source with a velocity 1/4 th of the velocity of sound. Then the ratio of the apparent frequency to actual frequency of source is

A source of sound crosses a stationary observer which is moving with uniform velocity v. If the velocity of sound in air is V, then the ratio of the apparent frequencies heard by the observer before and after the source crosses him would be -

An observer moves towards a stationary source of sound with a speed ((1)/(5)) th of the speed of sound. The wavelength and frequency of the source emitted are lamda and f, respectively. The apparent frequency and wavelength recorded by the observer are, respectively.