Question 19M.3.SL.TZ2.3a
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.SL.TZ2.3a |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Determine | Question number | a | Adapted from | N/A |
A student uses a Young’s double-slit apparatus to determine the wavelength of light emitted by a monochromatic source. A portion of the interference pattern is observed on a screen.
The distance D from the double slits to the screen is measured using a ruler with a smallest scale division of 1 mm.
The fringe separation s is measured with uncertainty ± 0.1 mm.
The slit separation d has negligible uncertainty.
The wavelength is calculated using the relationship .
When d = 0.200 mm, s = 0.9 mm and D = 280 mm, determine the percentage uncertainty in the wavelength.
[2]
Evidence of used ✔
«add fractional/% uncertainties»
obtains 11 % (or 0.11) OR 10 % (or 0.1) ✔
A very easy question about percentage uncertainty which most candidates got completely correct. Many candidates gave the uncertainty to 4 significant figures or more. The process used to obtain the final answer was often difficult to follow.
