An 18-mm-wide diffraction grating has rulings of 710 lines per millimieter. Monochromatic light of wavelength 506 nm wavelength is incident normally on the grating. What is the largest angle from the centerline at which an intensity maximum is formed?
A) 46°
B) 44°
C) 42°
D) 40°
E) 38°

Question

Quizplus · Accepted Answer

The diffraction angle for maximum intensity is given by the grating equation: d*sin(θ) = m*λ, where d is the distance between lines (1/710 mm), λ is the wavelength (506 nm), and m is the order of the maximum. The largest angle occurs at the highest possible m before sin(θ) exceeds 1. Calculating for m = 3 gives θ ≈ 46°.

An 18-Mm-Wide Diffraction Grating Has Rulings of 710 Lines Per