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?

The rate of decay (R ) of nuclei in a radioactive sample is plotted against time (t). Which of the following best represents the resulting curve ?

The rate of decay (R ) of nuclei in a radioactive sample is plotted against time (t) . Which of the following best represents the resulting 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 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.

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

If a source of frequency n moving with velocity v crosses a stationary observer, then the change in the frequency of sound heard by the observer will be (velocity of sound = V)

a bus is moving towards and stationary observer with speed 20 m/s blows a horn of frequency 200 Hz. the frequency of sound heard by the observer is approximately ( take speed of sound 320 m/s)