| Date | November 2016 | Marks available | 2 | Reference code | 16N.3.SL.TZ0.11 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 0 |
| Command term | Outline and State | Question number | 11 | Adapted from | N/A |
Question
Spherical converging mirrors are reflecting surfaces which are cut out of a sphere. The diagram shows a mirror, where the dot represents the centre of curvature of the mirror.
A ray of light is incident on a converging mirror. On the diagram, draw the reflection of the incident ray shown.
The incident ray shown in the diagram makes a significant angle with the optical axis.
(i) State the aberration produced by these kind of rays.
(ii) Outline how this aberration is overcome.
Markscheme
ALTERNATIVE 1
for incident ray, normal drawn which pass through C
reflected ray drawn such as i=r
i = r by eye
If normal is not visibly constructed using C,do not award MP1.
If no normal is drawn then grazing angles must be equal for MP2.
ALTERNATIVE 2
drawn second ray through C, parallel to incident ray
adds focal plane and draws reflected ray so that it meets 2nd ray at focal plane
Focal plane position by eye, half-way between C and mirror.
i
spherical «aberration»
ii
using parabolic mirror
OR
reducing the aperture
