A student has two diffraction gratings, a measuring tape, a ...

[formula1]

A student has two diffraction gratings, a measuring tape, a monochromatic light source of unknown wavelength, and a clamp a known distance L from the white wall to be used as a screen. One diffraction grating has a known distance d1 between slits; the other has the unknown distance we will call d2. To find the distance d2, the student must take which data?
  1.measure the distance from the central maximum to the first order maximum while the first diffraction grating is in the clamp
  2.measure the distance from the central maximum to the first order maximum while the second diffraction grating is in the clamp
  3.both of these choices
  4.None of these choicesthere are too many unknowns to find the distance in question.

Question 2

A physicist has two slits and two light sources to choose from, and wants to choose the configuration that will give the most data. The more maxima projected onto the screen, the more data. If slit 1 is smaller than slit 2, and the wavelength of source 1 is smaller than that of source 2, which ones should be used?<--EndFragment--> e?
  1.slit 1 and source 1
  2.slit 2 and source 2
  3.slit 2 and source 1
  4.slit 1 and source 2

[Joc]

Answer to Question 1

3

Answer to Question 2

3

[formula1]

Gracias!

[xiaomengxian]

Excellent