3.2 LIGHT

Exam-style questions

1 Figure 3.2.49 shows a ray of light PQ striking a

mirror AB. The mirror AB and the mirror CD are

at right angles to each other. QN is a normal to

the mirror AB.

A Figure 3.2.49

a State the value of the angle of incidence

of the ray PQ on the mirror AB.

b Copy the diagram, and continue the ray

[2]

PQ to show the path it takes after

reflection at both mirrors.

[3]

c State the values of the angle of reflection

at AB, the angle of incidence at CD and

the angle of reflection at CD.

[3]

d Comment on the path of the ray PQ and

the final reflected ray.

[2]

[Total: 10]

Alternative to Practical

3 You are asked to test the law of reflection,

You are given a set of pins, a plane mirror, a

protractor, a ruler, some modelling clay and a

large sheet of paper attached to a cork board.

Describe a method you could use to test

the law. Include a sketch of your proposed

experimental arrangement.

b Draw up a table with headings showing

what measurements you would take.

c How would you decide if your results were

in agreement with the law of reflection?

d Mention two precautions you would take

to ensure accurate results.

(4)

[2]

[2]

(2)

[Total: 10)

4 In Figure 3.2.51 a ray of light 10 changes

direction as it enters glass from air.

2 a Which of the following statements is a true

description of the image in a plane mirror?

A Upright, real and larger

C Inverted, real and smaller

B Upright, virtual and the same size

D Inverted, virtual and the same size

[1]

b A person stands in front of a mirror

(Figure 3.2.50). How much of the ror is

used to see from eye to to

2

Figure 3.2.51

[1]

a State the name given to this effect.

b Identify the normal.

c State whether the ray is bent towards or

away from the normal in the glass.

d State the value of the angle of incidence

in air.

(1)

[1]

[1]

[1]

[Total: 51

State the value of the angle of refraction

in glass.

5 Figure 3.2.52 shows rays of light in a semicircular

glass block.

A Figure 3.2.50

c A girl stands 5m away from a large plane

mirror. How far must she walk to be 2 m

away from her image?

A Figure 3.2.52

[4]

[Total: 7]

a Explain why the ray entering the glass at

A is not bent as it enters.

[1]

Bexplain why the ray AB is reflected at B and not refracted.

[2]

CRay CB does not stop at B. Copy the diagram and draw its approximate path after it leaves B.