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 equation:

d sinθ = mλ

where d is the distance between the slits, θ is the angle between the central spot and the first-order maximum, m is the order of the maximum (m=1 for first-order), and λ is the wavelength of the light.

Plugging in the given values, we get:

d sin(20.5°) = 1(632.8 nm)

Solving for d, we get:

d = 1(632.8 nm) / sin(20.5°) = 1.81 µm

Therefore, the correct answer is B.

A He-Ne Laser,which Produces Light of Wavelength 632