GCSE level optics questions
Q3.
The ray diagram shows the position and size of the image, I, of an object, O, formed by a lens, L.
![](diagram3ANS.png)
(a) What type of lens is shown in the ray diagram?
Convex OR converging lens. ![](../../../../graphics/symbols/nuclides/ticksmall.png)
(1 mark)
(b) Name the point labelled P.
Focal point or principal focus. ![](../../../../graphics/symbols/nuclides/ticksmall.png)
(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 ![](../../../../graphics/symbols/nuclides/ticksmall.png)
(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. ![](../../../../graphics/symbols/nuclides/ticksmall.png)
(1 mark)
(Total 5 marks)