Question

A beam of light of wavelength lambda = 541nm is normally incident on a diffraction grating which has 600 lines m * m ^ - 1 Determine the angle theta 2 at which the second order diffracted beam is seen.

Answer 1

Angle of diffraction for second order maxima is θ = 18.941°

Step-by-step explanation:

From the question it is given that

wavelength of incident light = λ = 541 nm = 541 x
`10^-^9 m`

order of maxima = n =2

diffraction grating has 600 lines per mm

⇒ distance between two slit is
`(1mm)/(600)` = 1.66 x
`10^-^6` m

using the relation of Braggs diffraction formula i.e.,

2dsinθ = nλ ..................................(1)

where, d = distance between two lines of grating

θ is the angle of diffraction

n= order of maxima

λ is the intensity of incident photon

on substituting the respected values in relation (1) we get,

2 x 1.66 x
`10^-^6`m sinθ = 2 x 541 x
`10^-^9 m`

⇒ sinθ = 0.3246

⇒ θ =
`sin^-^1(0.3246)` = 18.941 °