MCQ
If two waves of same frequency and same amplitude respectively, on superimposition produced a resultant disturbance of the same amplitude, the waves differ in phase by
  • A
    $\pi$
  • $2\pi /3$
  • C
    $\pi /2$
  • D
    Zero

Answer

Correct option: B.
$2\pi /3$
b
(b) ${A^2} = {a^2} = {a^2} + {a^2} + 2{a^2}\cos \theta$

$\Rightarrow \cos \theta = - \frac{1}{2} \Rightarrow \theta = \frac{{2\pi }}{3}$

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