White light is spread out into spectral hues by a grating. If the grating has 2000 lines per centimeter, at what angle will red light (640 nm) appear in the first order?
A)3.57°
B)7.35°
C)11.2°
D)13.4°
E)14.7°

Question

Quizplus · Accepted Answer

The angle for the first order can be calculated using the grating equation: d*sin(θ) = m*λ, where d is the distance between grating lines (1/2000 cm), m is the order (1), and λ is the wavelength (640 nm or 640 x 10^-7 cm). Solving for θ gives approximately 7.35°.

White Light Is Spread Out into Spectral Hues by a Grating