When monochromatic light illuminates a grating with 7000 lines per centimeter,its second order maximum is at 62.4°.What is the wavelength of the light?
A) 336 nm
B) 363 nm
C) 452 nm
D) 633 nm
E) 752 nm

Question

Quizplus · Accepted Answer

The formula for finding the angle of diffraction for a grating is:
sinθ = mλ/d
Where:
θ = angle of diffraction
m = order of diffraction (in this case, m = 2)
λ = wavelength of light
d = distance between adjacent slits on the grating (in this case, d = 1/7000 cm)

Rearranging the formula to solve for λ, we get:
λ = d sinθ /m

Plugging in the known values:
d = 1/7000 cm
m = 2
sinθ = sin(62.4°)

λ = (1/7000 cm) x sin(62.4°)/2 = 6.33 x 10^-7 cm

Converting to nm:
λ = 633 nm

Therefore, the wavelength of the light is 633 nm, which corresponds to answer choice D.

When Monochromatic Light Illuminates a Grating with 7000 Lines Per