A diffraction grating has 600 lines per millimetre and is illuminated by light of…
PHYSICS · Single correct · AP · Physics 2: Algebra-based · Waves Sound and Physical Optics · Waves Sound and Physical Optics
Problem
A diffraction grating has 600 lines per millimetre and is illuminated by light of wavelength 589 nm. What is the angle between the central maximum and the first-order maximum, and can the small-angle approximation reasonably be used for this situation?
(a) About 6.9∘; the approximation is justified
(b) About 42∘; the approximation is not justified
(c) About 21∘; the approximation is not justified
(d) About 21∘; the approximation is justified