Question

Two waves are said to have destructive interference if

• A. their frequencies are same
• B. their frequencies are doubled
• C. the phase difference is same
• D. the phase difference is ${180}^{\circ }$

Answer 1

The correct option is D the phase difference is ${180}^{\circ }$

Destructive interference happens, when the component waves producing the resultant wave are $\pi$ radians out of phase
The correct answer is (d)