A Helium-Neon Laser (λ = 632

Multiple Choice

A helium-neon laser (λ = 632.8 nm) is used to calibrate a diffraction grating. If the first-order maximum occurs at 20.5°, what is the line spacing, d?

A) 1.81 × 10−6 m
B) 1.00 × 10−5 m
C) 1.00 × 10−4 m
D) 1.31 × 10−6 m
E) 6.76 × 10−7 m