4.9 Diffraction Gratings

How many slits do diffraction gratings have?

• 1

• 2

• a lot

• 0

Experimentally, why are diffraction gratings easier to use compared to the 2-slit experiment?

• more interference is observed, so it's easier to see brighter maxima

• not as much interference is observed, so it's easier to see dark minima

• easier to hold a diffraction grating compared to a 2-slit device

• CD's are examples of diffraction gratings

What happens when you shine a white light through a diffraction grating?

• we observe a single large rainbow across the interference pattern

• each dark fringe is a rainbow

• each bright fringe is a rainbow

• jedi lightning is observed

True or false? A CD is an example of a transmission diffraction grating.

• True

• False

Light with a wavelength of 450 nm is shone through a diffraction grating with 1350 lines per cm. What will be the observed angle to the 3rd maximum?

• 7.4º

• 10.5º

• 11.9º

• 19.4º

A 582 nm wavelength light is shone through a diffraction grating. The observed angle to the 4th maximum is 13.7º. How many lines were on the diffraction grating?

• 1.02 * 10⁵

• 9.83 * 10^-6

• 9.83 * 10⁶

• 1.02 * 10^-5