Monochromatic light is normally incident on a diffraction grating that is 1 cm wide and has 10,000 slits.The first order line is deviated at a 30° angle.What is the wavelength of the incident light?
A)300 nm
B)400 nm
C)500 nm
D)600 nm
E)1000 nm

Question

Quizplus · Accepted Answer

The formula for the diffraction grating is:

d sin θ = nλ

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

In this problem, we know that:

d = 1 cm = 0.01 m
n = 1 (first order)
θ = 30°

Plugging these values into the formula and solving for λ, we get:

λ = d sin θ / n
λ = (0.01 m) sin 30° / 1
λ = 0.005 m
λ = 500 nm

Therefore, the wavelength of the incident light is 500 nm. The correct answer is C.

Monochromatic Light Is Normally Incident on a Diffraction Grating That