When light illuminates a diffraction grating with 7000 lines per centimeter,its second order maximum is at 62.4°.What is the wavelength of the light?
A)336 nm
B)363 nm
C)633 nm
D)752 nm

Question

Quizplus · Accepted Answer

The diffraction grating equation is given by:

mλ = d sinθ

where m is the order of the maximum, λ is the wavelength of light, d is the distance between adjacent slits in the grating, and θ is the angle between the incident light and the direction of the maximum.

Here, we are given that the grating has 7000 lines per centimeter, which means that the distance between adjacent slits is:

d = 1/7000 cm = 1.43 × 10^-4 cm

We are also given that the maximum is at the second order (m = 2) and at an angle of θ = 62.4°.

Substituting these values into the diffraction grating equation, we get:

2λ = (1.43 × 10^-4 cm) sin62.4°

Simplifying and solving for λ, we get:

λ = (1.43 × 10^-4 cm) sin62.4° / 2

λ ≈ 633 nm

Therefore, the best choice is C, with a wavelength of 633 nm.

When Light Illuminates a Diffraction Grating with 7000 Lines Per