Two speakeer connected to the same source of fixed frequency are placed 2m apart in a box. A sensitive microphone placed at a distance of 4m from the midpoint alon the perpendicular bisector shown maximum response. The box is slowly rotated till the speaker are in line with the microphone, The distance between the midpoint of the speakers and the microphone remains unchanged. Exactly 5 maximum responses (inculuding the initial and last one) and observed in the microphone in doing this. The wavelength of the sound wave is (o.x) meter. Find the value of x.

Explanation

As shown in Figure,(a)
initially `S_1 M =S_2M,Deltax =0`., at M, there is zero order maxima.

According to the given problem on rotatinof speakers about O when `S_1 and S_2` are in line with microphone M as shown in figure (b),
5 maximum reponses are observed.
i.e.,` S_2M - S_1M =5 lambda" or " S_2 S_1 = 5 lambda`
`i.e., lambda =2//5 =0.4 m [as S_1S_2 =2m]`