Question 22N.2.HL.TZ0.7a.ii
| Date | November 2022 | Marks available | [Maximum mark: 2] | Reference code | 22N.2.HL.TZ0.7a.ii |
| Level | HL | Paper | 2 | Time zone | TZ0 |
| Command term | Explain | Question number | a.ii | Adapted from | N/A |
A beam of coherent monochromatic light is incident normally on a single rectangular slit. The diffraction pattern is observed on a screen.
O is the point on the screen directly opposite the slit. P and Q are the first minima on either side of the central fringe of the diffraction pattern.
Early theories of light suggest that a geometrical shadow of the slit will be observed on the screen. Explain how the diffraction pattern formed on the screen provides evidence for the wave theory of light.
[2]
observed pattern goes beyond the rectangular shape/geometrical shadow
OR
observed pattern shows maxima/minima ✓
«this is explained by» interference/superposition of waves ✓
Accept any correct description of the diffraction pattern for MP1.
Well answered. Most candidates scored a mark with specific reference to interference/superposition of waves although some missed a clear reference to a detail of the diffraction pattern or a reference of the discrepancy between this pattern and the geometrical shadow expected.
