When light illuminates a grating with 7000 lines per centimeter,its second order maximum is at 62.4°.What is the wavelength of the light?

Question

Quizplus · Accepted Answer

The formula for finding the angle of diffraction for a grating is given by:

nλ = d*sinθ

where n is the order of the maximum (in this case, n=2), λ is the wavelength of light, d is the spacing between the grating lines, and θ is the angle of diffraction.

We are given that the grating has 7000 lines per centimeter, which means that the spacing between the lines is:

d = 1/7000 cm = 10^-5 m

The second-order maximum occurs at an angle of θ = 62.4°. Plugging these values into the formula above, we get:

2λ = (10^-5)*sin(62.4°)

λ = (10^-5)*sin(62.4°)/2

λ ≈ 633 nm

Therefore, the wavelength of the light is 633 nm, which is answer choice C.

When Light Illuminates a Grating with 7000 Lines Per Centimeter,its