An oscillator of frequency `680 Hz` drives two speakers . The speakers are fixed on a vertical pole at a distance `3 m` from each other as shown in Fig. 7.103. A person whose height is almost the same as that of the lower speaker walks towards the lower speaker in a direction perpendicular to the pole. Assuming that there is no reflection of sound from the ground and speed of sound is `v = 340 m//s` , answer the following questions.

As the person walks toward the pole , the total number of times that the person hears a minimum in sound intensity will be

Options

A. 2
B. 8
C. 4
D. 6

Answer

D