Physics - Wave Optics Question with Solution | TestHub

For dark fringes in Young's double slit experiment, destructive interference takes place.

The condition for destructive interference is that the phase difference between the two interfering waves must be an odd multiple of $\pi$.

Therefore, the phase difference is given by $\Delta \varphi =(2n-1)\pi$, where $n$ is an integer.

Answer: $(2\mathrm{n}-1)\pi$