Question 10
(a) List the three secondary colours of light.
(b) 
The diagram above illustrates a defect of the human eye.
(i) State the type of defect.
(ii) Name the type of lens to be used in correcting the defect.
(c)
An object O is placed between two plane mirrors inclined at right angles to each other as illustrated in the diagram above.
(i) Calculate the number of images formed.
(ii) Copy the diagram.
(iii) On the copied diagram, locate and label all the positions of the images formed by the mirrors.
(d) A mirror of focal length 60.0 cm is used to produce a virtual image 3 times larger than the object. Determine the image distance from the mirror.
Observation
Part (a): Performance was above average. Majority of the candidates attempted and obtained full mark.
Part (b): Performance was above. Most candidates were able to provide the correct response to both (i) and (ii).
Part (c): Performance was fair. Candidates had difficulty in writing the correct formula in (i). Many candidates did not copy the given diagram correctly in (ii) and failed to locate the three correct images.
Part (d): Performance was fair. Many candidates got the right response but some lost some marks due to inability to correctly solve the given problem.
The expected answer is:
10.(a) Secondary Colours of Light
- cyan;
- magenta;
- yellow.
(b)(i) Long sightedness/hypermetropia
(ii) Converging lens
