# Lab 10 Pre-Lab

(Note: No spaces, no dashes, no mistakes! If you type your ID wrong, I'm afraid you won't end up getting credit)

Due date: Mon Nov 21 before class.

Normally these questions will be submitted online AND you will print out a copy to turn in to your TA (If you fail to turn something in to your TA, you will get no PRELAB credit. Only copies of the online submissions will be accepted.)

PRELAB QUESTIONS: (to be turned in upon arriving at lab)

Reflections: Lab 9 Diffraction and Interference

1. I thought this lab was __________ USEFUL for learning about ray optics and lenses.

very
pretty
somewhat
barely
not at all

2. I thought this lab was __________ ENJOYABLE for a physics lab.

very
pretty
somewhat
barely
not at all

3. A two-slit interference pattern is viewed on a screen. The separation of the slits, d, is slowly decreased. What happens to the pattern on the screen?

The fringes move closer together.
The fringes move further apart.
There is no change in the fringe separation.
None of the above

Prelab 10 Questions:

1. For a given order (say m=3), is the angle of diffraction for red light larger or smaller than the angle for blue light? Explain.

2. In part 2 of this experiment, how will you determine the spacing d of your diffraction grating?

3. What is the relation between the energy E and the frequency f of a photon?

4.The colors of the four lines of the hydrogen spectrum are: red, blue-green, and two shades of violet. Which initial states ni = 3, 4, 5, or 6 correspond to these colors? (Hint: The colors of the visible spectrum, from longest to shortest wavelengths, are: red, orange, yellow, green, blue, violet.)

5.Transitions to the n=1 (ground state) level from higher levels in the hydrogen atom never produce visible wavelength photons. Are the wavelengths produced by transitions to the n=1 level longer or shorter than visible λ's? Explain.

6.In part 2 of this experiment, which quantities are given, which are measured directly, and which are calculated?

Thanks for your time and efforts!

Optional! - below is a space for any additional relevant comments, thoughts, or suggestions you have. If you want to elaborate on any "multiple choice" questions, do so here. It can also be about anything you'd like to tell or ask relating in some way to this class! If you expect a reply, however, it's much better to email Prof. Finkelstein.

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