Diffraction grating: A He-Ne laser, which produces light of wavelength 632.8 nm, is used to calibrate a diffraction grating. If the first-order maximum occurs at 20.5° from the central spot, what is the distance between the slits of the grating?
A) 0.905 µm
B) 1.81 µm
C) 2.20 µm
D) 3.62 µm
E) 4.52 µm

Question

Quizplus · Accepted Answer

The distance between the slits of the grating can be calculated using the formula:

d * sin θ = mλ

where d is the distance between the slits, θ is the angle of diffraction, m is the order of the maximum, and λ is the wavelength of the light.

In this case, we have:

d * sin 20.5° = (1) * 632.8 nm

Solving for d, we get:

d = (1 * 632.8 nm) / sin 20.5°

d ≈ 1.81 µm

Therefore, the correct answer is B.

Diffraction Grating: a He-Ne Laser, Which Produces Light of Wavelength