An 18-mm wide diffraction grating has rulings of 880 lines per mm.Monochromatic light of 590 nm wavelength is incident normally on the grating.What is the largest angle,measured from the central bright spot,at which an intensity maximum is formed?
A) 31°
B) 29°
C) 27°
D) 25°
E) 23°

Question

Quizplus · Accepted Answer

The diffraction angle can be found using the grating equation: d*sin(θ) = m*λ, where d is the distance between lines (1/880 mm), λ is the wavelength (590 nm), and m is the order of the maximum. The largest angle occurs at the highest possible m where sin(θ) ≤ 1. Calculating for m = 3 gives the largest angle of approximately 31°.

An 18-Mm Wide Diffraction Grating Has Rulings of 880 Lines