White light is spread out into spectral hues by a diffraction grating. If the grating has 1 000 lines per cm, at what angle will red light (l = 640 nm) appear in first order?
a. 14.7
b. 7.35
c. 17.7
d. 3.67
e. 1.84
Question 2
A helium-neon laser (l = 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