Question

Intensity and phase of three sound wave reaching at some point in space is I₀, 4 I₀, I₀ and 10⁰, 130⁰ and 250⁰ respectively. Resultant intensity at that point will be –

• A. 6 I₀
• B. 2I₀
• C. I₀
• D. $\left( \frac{2 + \sqrt{3}}{\sqrt{2}} \right)I_{0}$

Answer 1

Answer: (C)

I₀

Answer 2

Amplitude of the three sound wave would be in ratio 1 : 2 : 1. Let amplitude of first wave be A.

Figure 1

Figure 2

\ A_R = A

̃ I_R µ A²

\ I_R = I₀