A diffraction grating that has 4500 lines/cm is illuminated by light that has a single wavelength. If a second order maximum is observed at an angle of 42° with respect to the central maximum, what is the wavelength of this light?
A)1500 nm
B)370 nm
C)930 nm
D)1100 nm
E)740 nm

Question

Quizplus · Accepted Answer

The diffraction grating equation is d*sin(θ) = m*λ, where d is the distance between grating lines (1/4500 cm), θ is the angle (42°), m is the order (2), and λ is the wavelength. Solving for λ gives approximately 740 nm.

A Diffraction Grating That Has 4500 Lines/cm Is Illuminated by Light