A student investigates the wavelength of a red laser by measuring several diffraction minima produced by a single slit of width 0.080mm. The screen is placed 1.60m from the slit. The measured vertical distances ym (each on the same side of the central maximum) are recorded in the table.
Order number m
1
2
3
4
ym (mm)
12.7
25.3
38.0
50.6
You may assume all angles involved are small.
(a) Assign the appropriate order number to each measurement and explain how the sign convention for m relates to the symmetry of the pattern.
(b) Graph ym versus m and determine the best-fit slope. Show numerical work leading to the slope value in SI units.
(c) Use the slope found in part (b) to calculate the wavelength of the laser light.
(d) The manufacturer states that the laser’s nominal wavelength is 630nm. Calculate the percent error of the experimental value and discuss how using multiple orders, rather than a single order, affects both accuracy and precision.