1. Explain why the separation of the two slits is 2h.
2. Observe and comment on the patterns you see in the interference fringes as the spacing is changed.
3. Using our calibration of D0 validated by the direct measurement with a scale in # 4, what is the slit separation h in each case for dial readings — 43, 45, 47, 49, 51, 53, and 55 that produced the fringe patterns in these images? Note that the uncertainty in the dial reading is ±1. What uncertainty will this introduce into a measurement of wavelength that depends on d?
4. Based on that image, what is the ratio of the wavelength or red light to the wavelength of blue light?
5. A. Describe how you made the measurements using the images on the screen and the scale below them. Estimate the errors in the fringe spacing for each case, and then pair up the separation of the slit and its mirror image d with the spacing of the dark fringes Δx and report them here.
The wavelength of the light responsible for the patterns would be
lambda equals space left parenthesis capital delta x right parenthesis cross times left parenthesis d divided by ell right parenthesis
λ = (Δx d / ℓ)
as describe on the class website.

B. For each one, find a wavelength, then average them to give a mean value with a standard deviation for the set of data. Convert this average and its uncertainty to the commonly uses units of angstroms, microns, and meters.

C. In the image for the dial reading 45, the white fringes are big and show obvious color. What is the ordering of the colors and why does that occur?

While we encourage collaboration and using resources outside of the class environment too, answers here should be in your own words with an explanation that reflects your understanding of the lab. If you use sources other than the class website, you should cite them here.