Question

There is a destructive interference between the two waves of wavelength $\lambda$coming from two different paths at a point. To get maximum sound or constructive interference at that point, the path of one wave is to be increased by

• A. $\lambda/4$
• B. $\lambda/2$
• C. $\frac{3\lambda}{4}$
• D. $\lambda$

Answer 1

Answer: (B)

$\lambda/2$

Answer 2

Destructive interference means the path difference is

$(2n - 1)\frac{\lambda}{2}$

B]f it is increased by $\lambda/2$

Then new path difference (2n – 1) $\frac{\lambda}{2} + \frac{\lambda}{2}$= n$\lambda$

which is the condition of constructive interference.