Question

What is the wavelength in nm of a light whose first order bright band forms a diffraction angle of 30 degrees, and the diffraction grating has 700 lines per mm? ​

Answer 1

Answer:

The wavelength is 3500 nm.

Explanation:

d= $\frac{1}{700 lines per mm} = 0.007mm = 7000 nm$

n= 1

θ= 30°

λ= unknown

Solution:

d sinθ = nλ

λ = $\frac{7000 nm sin 30}{1}$

λ = 3500 nm