Date | November 2018 | Marks available | 3 | Reference code | 18N.3.SL.TZ0.8 |
Level | Standard level | Paper | Paper 3 | Time zone | 0 - no time zone |
Command term | Label and Draw | Question number | 8 | Adapted from | N/A |
Question
The refractive index of glass decreases with increasing wavelength. The diagram shows rays of light incident on a converging lens made of glass. The light is a mixture of red and blue light.
On the diagram, draw lines to show the rays after they have refracted through the lens. Label the refracted red rays with the letter R and the refracted blue rays with the letter B.
Suggest how the refracted rays in (a) are modified when the converging lens is replaced by a diverging lens.
Hence state how the defect of the converging lens in (a) may be corrected.
Markscheme
each incident ray shown splitting into two ✔
each pair symmetrically intersecting each other on principal axis ✔
for red, intersection further to the right ✔
For MP3, at least one of the rays must be labelled.
rays diverge after passing through lens
OR
the extension of the rays will intersect the principal axis on the side of incident rays/as if they were coming from the focal point/points in the left side/OWTTE ✔
by placing a diverging lens next to the converging lens
OR
make an achromatic doublet ✔