A diffraction grating has 5000 lines per cm. When illuminated with monochromatic light of wavelength 600 nm, what is the angle for the second-order maximum?

Core Concept

The diffraction grating equation is d sinθ = mλ, where d is the spacing between lines, m is the order, and λ is the wavelength. First, find d = 1/5000 cm = 2×10^-6 m. For m=2 and λ=600 nm=6×10^-7 m, we get sinθ = (2 × 6×10^-7)/(2×10^-6) = 0.6. Therefore, θ = arcsin(0.6) = 17.2°.