Question

Light of wavelength 550 nm falls on a slit that is 3.50 x 10^-3 mm wide. How far from the central . maximum will the first diffraction maximum fringe be if the screen is 10.0 m away?

Answer 1

λ
`= 550 * 10^(-9)\] m. D = 3.50*10^-6 m.`

`d = 10 m. m = 1 2x = ?`

Then you need to find x when n=1
or

`sinθ=λ/w=524x10^-9/0.0033=1.59x10^-4`
≈θ for θ<<1 , so θ=
`1.59x10^-4 radians`

Then you can find rhe distance of bright fringe from the center:
`d= θD=1.59x10^-4x10m ≈ 1.6 mm`