1
1 Red light travelling in air strikes the curves surface of a semi-circular glass block at P.
The diagram shows the ray of light.
The light travels in a straight line from O to Q.
(a) Explain why the light does not change direction as it enters the glass block at P.
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........................................................................................................................................... [1]
(b) The light travels in the glass to Q where it strikes the edge of the block at 30° to the normal.
The light then emerges into the air.
(i) The refractive index of the glass is 1.5.
Calculate the angle between the normal and the ray in the air after the light emerges
from the block at Q.
angle = ............................................ [3]
(ii)
On the diagram, sketch the path of the light in the air after it emerges at Q. [1]
2
(c) The direction of the light striking the curved surface of the glass block is changed. The angle
between the ray and the normal at Q gradually increases from 30° to 90°.
Describe what happens to the light that strikes the block at Q as this angle increases.
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........................................................................................................................................... [3]
[Total: 8]
2 The distance between the centre of a thin converging lens and each principal focus is 5.0 cm.
The lens is used as a magnifying glass to produce an image I of an object O.
The diagram is a full-scale diagram of the lens and the image I.
(a) (i) On the diagram, mark both principal focuses and label each of them F.
[1]
(ii) By drawing on the diagram, find the position of object O and add object O to the diagram.
[3]
3
(b) Using the diagram, determine the distance of object O from the centre of the lens.
distance = .............................................. [1]
[Total: 5]
3 The diagram shows a converging lens and the image I formed when an object is placed to the left
of the lens. The principal focuses are labelled A and B and the centre of the lens is labelled C.
(a) On the diagram, draw two rays to locate the position of the object. Draw the object and label
it O. [3]
(b) Ring all of the following distances that are equal to the focal length of the lens.
AB AC CB 2AB
[2]
[Total: 5]
4
4 The diagram shows an incomplete ray diagram of a converging lens forming an image of the
object, O.
(a) On the diagram, draw a ray of light from the top of the object that passes through the lens to
form the image. Use a ruler. [2]
(b) On the diagram, draw the image formed by the lens. Label the image I. [1]
(c) Choose words from the box that describe the image formed by the lens in the diagram.
diminished enlarged horizontal inverted same size upright
Draw a ring around each correct word. [2]
[Total: 5]
