A diffraction grating is illuminated normally.
The third-order maximum for light of wavelength 480 nm480\text{ nm}480 nm occurs at the same angle as the second-order maximum for light of wavelength λ\lambdaλ.
What is λ\lambdaλ?
320 nm320\text{ nm}320 nm
480 nm480\text{ nm}480 nm
720 nm720\text{ nm}720 nm
1080 nm1080\text{ nm}1080 nm
