Question

A narrow pulse (for example, a short pip by a whistle) is sent across a medium. 

(a) Does the pulse have a definite 

(i) frequency, (ii) wavelength, (iii) speed of propagation? 

(b) If the pulse rate is 1 after every 20 s, (that is the whistle is blown for a split of second after every 20s), is the frequency of the note produced by the whistle equal to 1/20 or 0.05 Hz.

Answer 1

(a) A narrow pulse does not have a definite wavelength or frequency. But being a sound, it has a definite speed. 

(b) The frequency of the note produced by the whistle is not equal to 1/20 or 0.05 Hz, it is only the frequency of pulse repetition.