Light from an argon laser strikes a diffraction grating that has 5,139 grooves per centimeter. The central and first-order principal maxima are separated by 0.488 m on a wall 1.78 m from the grating. Determine the wavelength of the laser light.

515.5 nm

Explanation:

To find the wavelength (λ) of the laser light we can use the following equation:

Where:

n: is the order of the principal maxima = 1

d: is the width of the groove = 1/N

N: is the number of grooves per length = 5139 grooves/cm

θ: is the angle made by the spectral line → tanθ = D/L

D: is the separation from the wall = 0.488 m

L: is the separation from the grating = 1.78 m

First, we have to find d and θ:

Now, we can calculate the wavelength of the laser light:

Therefore, the wavelength of the laser light is 515.5 nm.

I hope it helps you!