A train whistling at constant frequency is moving towards a station at a constant speed V. The train goes past a stationary observer on the station. The frequency `n^(')` of the sound as heard by the observer is plotted as a function of time t, figure. Identify the expected curve.

A train whistling at constant frequency is moving towards a station at a constant speed V. The train goes past a stationary observer on the station. The frequency n' of the sound as heard by the observer is plotted as a function of time t (shown in the figure). Identical the expected curve.

A train whistling at constant frequency 'n' is moving towards a station at a constant speed V. The train goes past a stationary observr on the station . The frequecy 'n' of the sound as heard by the observe is plotted as function of time 't' . Identify the correct curve .

A railway engine whistling at a constant frequency moves with a constant speed. It goes past a stationary observer standing beside the railway track. The frequency (n) of the sound heard by the observer is plotted agains time (t) . Which of the following best represents the resulting curve?

A railway engine whistling at a constant frequency moves with a constant speed and it goes past a stationary observer standing beside the railway track. Then the frequency of (n') of the sound heard by the observer with respect to time (t) can be best represented by which of the following curve?

A sound source, emitting sound of constant frequency, moves with a constant speed and crosses a stationary observer. The frequency (n) of sound heard by the observer is plotted against time (t). Which of the following graphs represents the correct variation :-

A railway engine whistiling at a constant frequency moves with a constant speed. It goes past a stationary observer beside the railyway track. Which of the following graphs best represent the variation of frequnecy of the sound (n) heard by the observer with the time (t) ?

An engine whistling at a constant frequency n_0 and moving with a constant velocity goes past a stationary observer. As the engine crosses him, the frequency of the sound heard by him changes by a factor f. The actual difference in the frequencies of the sound heard by him before and after the engine crosses him is

A source of sound when moves towards a stationary observer, then frequency of the sound heard by listener is more than actual frequency because the