Question

We find the phase difference after which we put that into the phy which is equal to 2 Pi by Lambda into X the phase difference so I want to know what is that phy like a name just like how X has path difference name

Answer 1

Phase difference

Answer 2

The equation $\phi = \frac{2\pi}{\lambda} X$ relates the phase difference ($\phi$) to the path difference ($X$) for a wave, where $\lambda$ is the wavelength. The term $\phi$ in this standard formula represents the phase difference.