GCSE level optics questions


The ray diagram shows the position and size of the image, I, of an object, O, formed by a lens, L.

(a) What type of lens is shown in the ray diagram?

Convex OR converging lens.

(1 mark)

(b) Name the point labelled P.

Focal point or principal focus.

(1 mark)

(c) The ray diagram has been drawn to scale. Calculate the magnification of the object by the lens. Show clearly how you work out your answer.

Magnification = height of image/height of object = 6 mm/4 mm = 1.5

(2 mark)

(d) How can you tell from this ray diagram that the image is a real image?

The rays meet at a point - therefore a real image is formed at that point.

(1 mark)

(Total 5 marks)