In a single slit diffraction method, the distance between slit and screen is `1m`. The size of the slit is `0.7mm` and second maximum is formed at the distance of `2mm` from the centre of the screen, then find out the wavelength of light.

Explanation

Path difference
`a sin theta. =(5lambda)/(2)`
`a sin theta=(5lambda)/(2)`
`a.y/D=(5lambda)/(2)`
`lambda=(2ay)/(5D)=(2xx0.7xx10^(-3)xx2xx10^(-3))/(5xx1)`
`=(28)/(5)xx10^(-7)=5600Å`