6 Fig. 6.1 shows an object, the tip of which is labelled O, placed near a lens L.
The two principal foci of the lens are F1 and F2.
L O
F2 F1
L
Fig. 6.1
(a) On Fig. 6.1, draw the paths of two rays from the tip of the object so that they pass
through the lens and continue beyond.
Complete the diagram to locate the image of the tip of the object. Draw in the whole
image and label it I. [3]
(b) Describe image I.
Formed image is virtual upright
..........................................................................................................................................
magnified at same side of ta
..........................................................................................................................................
object
..........................................................................................................................................
.................................................................................................................................... [3] [Total: 6]
8 Fig. 8.1 shows a thin converging lens. The two principal foci are shown.
if principal
F2 F1 axis
A vertical object, 2 cm tall, is to be positioned to the left of the lens, with one end on the
principal axis.
On Fig. 8.1,
draw the object in a position which will produce a virtual image, labelling the object with
the letter O, [1]
draw two rays showing how the virtual image is formed, [2]
draw in the image, labelling it with the letter I. [1]
[Total: 4]
5 Fig. 5.1 is drawn full scale. The focal length of the lens is 3.0 cm.
i s
lens
Fig. 5.1
(a) On Fig. 5.1, draw two rays from the top of the object O that meet at the image. [2]
(b) (i) Define the term linear magnification.
It is the ratio between height of
..................................................................................................................................
image height of object
..................................................................................................................................
............................................................................................................................ [1]
(ii) Determine the magnification produced by the lens in Fig. 5.1. M 90 0 6
0.6
magnification = ................................................ [1]
Q. A burning candle is placed close to a thin converging lens. The candle acts as the object.
A white, vertical screen is moved to a position on the other side of the lens from the candle.
Fig. 6.1 is a full-scale diagram, on graph paper, of the lens and the screen.
lens screen 0.2
5
21
Fifteen image of
candle
2cm 702cm
The focal length of the lens is 2.4 cm. The screen is 7.2 cm from the centre of the lens. A sharply
focused, inverted image of the candle is produced on the screen, as shown in Fig. 6.1.
Define the term focal length.
It is the distance between optical
...................................................................................................................................................
center focal point
...................................................................................................................................................
.............................................................................................................................................. [1]
On Fig. 6.1, mark and label with an F, each of the two focal points (principal foci) of the
lens. [1]
The point Y is the tip of the image.
On Fig. 6.1, draw a ray diagram to locate the position of the top of the object.
Label this point X. [3]
Using Fig. 6.1, determine the distance of the candle from the centre of the lens.
ii1/o1v
Q The camera lens shown in Fig. is used to photograph the object O.
camera lens
Fig. (full scale)
The object O is 2.0 cm high and is placed 8.0 cm from the centre of the lens. The lens has a focal length of 3.0 cm.
(i) Draw rays on Fig. to find the position and height of the image formed by the lens.
Label the image I. [3]
(ii) Determine the height of the image.
.......................................................................................................................................[1]
The image formed by the lens is a real image.
Explain the difference between a real image and a virtual image.
....................................................................................................................................
....................................................................................................................................
................................................................................................................................[1]
Explain how a converging lens is used to produce and view a virtual image.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
1 Convex lenses are used in cameras and as magnifying glasses.
Which types of image are formed?
type of image in type of image in
camera magnifying glass
A real real
B real virtual
C virtual real
D virtual virtual
2 An object is viewed through a concave (diverging) lens.
What is the correct description of the image formed?
A real, inverted, magnified
B real, upright, diminished
C virtual, inverted, magnified
D virtual, upright, diminished
3 The ray diagram shows two rays from a point on an object placed in front of a diverging
(concave) lens.
What are the properties of the image produced?
A real and larger than the object
g B real and smaller than the object
object C virtual and larger than the object
D virtual and smaller than the object
diverging
lens
4 The diagram shows rays of light.
What is in the space labelled X?
A a converging lens
I
X
B a diverging lens
C a plane mirror
D a rectangular glass block
5 Which length is the focal length of the lens?
A B C
lens
D
6 The diagram shows a thin converging lens of focal length f.
Where must an object be placed to produce a real image in the position shown?
A B C D
f f
image
7 Which row applies to a short-sighted eye viewing a distant object?
position of the image lens needed for correction
A behind the retina converging lens
B behind the retina diverging lens
C in front of the retina converging lens
D in front of the retina diverging lens
8 An object 5.0 cm high is placed 2.0 cm from a converging (convex) lens which is being used as a
magnifying glass.
The image produced is 6.0 cm from the lens and is 15 cm high.
cm
15
10
cm
6 5 4 3 2 1 0 1 2 3 4 5 6
image object
converging lens
What is the focal length of the lens?
A 2.0 cm B 3.0 cm C 4.0 cm D 6.0 cm
9 The rays of light from a ray-box pass through three lenses placed at positions 1, 2 and 3.
ray-box
What type of lens is used at each position?
position 1 position 2 position 3
position 1 position 2 position 3
A converging converging converging
B converging converging diverging
C diverging converging diverging
D diverging diverging converging
