DP Physics (last assessment 2024)
Question 19M.2.HL.TZ2.ci
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.2.HL.TZ2.ci |
| Level | HL | Paper | 2 | Time zone | TZ2 |
| Command term | Suggest | Question number | ci | Adapted from | N/A |
ci.
[Maximum mark: 1]
19M.2.HL.TZ2.ci
Monochromatic coherent light is incident on two parallel slits of negligible width a distance d apart. A screen is placed a distance D from the slits. Point M is directly opposite the midpoint of the slits.
Initially the lower slit is covered and the intensity of light at M due to the upper slit alone is 22 W m-2. The lower slit is now uncovered.
The width of each slit is increased to 0.030 mm. D, d and λ remain the same.
Suggest why, after this change, the intensity at P will be less than that at M.
[1]
Markscheme
«the interference pattern will be modulated by»
single slit diffraction ✔
«envelope and so it will be less»
Examiners report
Many recognised the significance of the single slit diffraction envelope.
