Question

What is path difference formula?

Answer 1

1. Path difference is the difference in the path traversed by the two waves.
2. The general formula for destructive interference due to path difference is given by
   $\delta =\left(m+\frac{1}{2}\right)\frac{\lambda }{n}$
   Where, $n$ is the refractive index, $\delta$ is the path difference, $\mathrm{\lambda }$ is the wavelength of the wave and the number of order $m=0,1,2,3.....$
   
3. Any two-wave with the same frequency, path differences are related as
   $∆x=\frac{\lambda }{2\pi }∆\varnothing$
   Where, $∆x$ is the path difference between the two waves, $\mathrm{\lambda }$ is the wavelength of the wave and $∆\varnothing$ is the phase difference between two waves.