Two sources of sound S 1 and S 2 vibrate at same frequency and are in phase (figure 16-E8). The intensity of sound detected at a point P as shown in the figure is I 0 . (a) If θ equals 45°, what will be the intensity of sound detected at this point if one of the Sources is switched off? (b) What will be the answer of the previous part if θ = 60 o ?

Question

Philoid · Accepted Answer

Given:
Resultant intensity at P = I₀

The two sources of sound S₁ and S₂ vibrate with the same frequency and are in the same phase.

(a) When θ = 45°:
Path difference = S₁P − S₂P = 0

So, when the source is switched off, the intensity of sound at P is

(b) When the path difference is also. Similarly, it can be proved that the intensity at P is

When the source is switched off.