Question

Monochromatic light is incident on a grating that is 75 mm wide and ruled with 50,000 lines. the second-order maximum is seen at 32.5°. what is the wavelength of the incident light?

Answer 1

Answer:

The wavelength of the incident light is $\lambda =$ 400 nm

Explanation:

Given data

Distance between the sits

$d = \frac{0.075}{50000}$

d = 1.5 × $10^{-6}$ m

$\theta = 32.5$°

m = 2

We know that the wavelength of the incident light is given by

$\lambda = \frac{d\sin \theta}{m}$

Put all the value in above formula we get

$\lambda = \frac{1.5 (\sin 32.5)}{2}$×$10^{-6}$

$\lambda =$ 4 × $10^{-7}$ m

$\lambda =$ 400 nm

Therefore the wavelength of the incident light is $\lambda =$ 400 nm