Alternative B
Question 2B
(b) (i) In a projection lantern, at what distance from the lens should the slide be placed to obtain an erect, large image on the screen?.
(ii) An object has its erect image formed 30 cm from a converging lens. If the focal length of the lens is 15 cm, how many times is the image bigger than the object?
Observation
Part (b) Candidates’ response was fair.
The expected response:
(b) (i) Distance to place slide to obtain erect and large image
Distance greater than f but less than 2f
(ii) 
u = 10
m = 
= 
= 3