An observer `A` is moving directly towards a stationary sound source while another observer `B` is moving away from the source with the same velocity. Which of the following statements are correct?

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

The observer is moving with velocity 'v'_(0) towards the stationary source of sound and then after crossing moves away from the source with velocity 'v'_(0) . Assume that the medium through which the sound waves travel is at rest. If v is the velocity of sound and n is the frequency emitted by the source, then the difference between appearent frequencies heard by the observer is

The observer is moving with velocity 'v_0' towards the stationary source of sound and then after crossing moves away from the source with velocity ' v_0 '. Assume that the medium through which the sound waves travel is at rest, If 'v' is the velocity of sound and 'n' is the frequency emitted by the spurce then the difference between apparent frequencies heard by the observer is

A source of sound emitting a note of frequency 200 Hz moves towards an observer with a velocity v equal to the velocity of sound. If the observer also moves away from the source with the same velocity v, the apparent frequency heard by the observer is

A source of sound emitting a note of frequency 200 Hz moves towards an observer with a velocity v equal to the velocity of sound. If the observer also moves away from the source with the same velocity v, the apparent frequency heard by the observer is

An observer moves towards a stationary source of sound. The percentage change in the apparent frequency is

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

An observer moving towards a stationary source observes that the apparent frequency is three times the actual frequency of the source. If the velocity of sound is V, the velocity of the observer would be-