Physics - Sound Wave Question with Solution | TestHub

If the waves interfere destructively, then path difference is given by $\frac{\lambda }{2},\frac{3\lambda }{2},\frac{5\lambda }{2}$ etc. Therefore path difference of a destructive interference is $\frac{(2n+1)\lambda }{2}$ (where $n=1,2,3,\dots )$ etc.