Question

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

[MP PMT 1990; MP PET 2000]

• A.
• B.
• C.
• D. Zero

Answer 1

The correct option is B

$A^2=a^2=a^2+a^2+2a^{2}cos\theta \Rightarrow cos\theta =-\frac{1}{2}\Rightarrow \theta =\frac{2\pi }{3}$