Name:___________________
Physics 11 Light and Sight Test
1
A convex lens is being used as a magnifying glass.
A Sketch a ray diagram to show how a convex lens can produce an upright
magnified image of an object
(2 marks)
B If the convex lens has a focal length of 12.0 cm and the object is 8.0 cm from
the lens
(i)
Find the distance from the lens to the image
(2 marks)
(ii)
The magnification
(1 mark)
2
Dentists sometimes use a small curved mirror to produce a magnified image of the
patient's tooth.
A What type of curved mirror would the dentist use?
(1mark)
B Draw a ray diagram to show how this type of mirror can produce a magnified
image.
(2 marks)
C Is the image real or virtual? Explain.
(1 mark)
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3
An opaque container used to hold water is 1.00 m high and 1.00 m wide. The
inner surface of the container is marked with a series of graduations to indicate
the water depth. The graduations are every centimetre with 0 cm at the bottom
and 100 cm at the top.
With the container empty, I position myself so that 1 can just see the 50 cm
graduation, but none below it. I do not move from this position.
My friend starts to fill the container with water of refractive index 1.33.
A What graduation mark can 1 just see when the water depth is 40 cm?
(1 mark)
B As the water level goes above the 50 cm mark, 1 notice that 1 can see below
the 50 cm mark. What is the name given to this "bending" effect?
(1 mark)
C Draw a sketch showing how I can see below the 50 cm graduation.
(2 marks)
4
A ray of white light strikes a glass prism as shown below.
White
Light
ray
Refractive index of air 1.00
Refractive index for red light 1.51
Refractive index for blue light 1.53
On emerging from the prism, the white light has been split into several colours.
A What is the name given to this effect?
(1 mark)
B Draw a sketch showing how the white light passes through and emerges from
the prism. Label any coloured rays.
(2 marks)
C Calculate the angle of dispersion (i.e. the angle between the emerging red and
blue rays).
(3 marks)
5
A large camera is to be built with a lens-to-film distance of 30.0 cm.
A What lens focal length would be appropriate to photograph objects at infinity? ie
objects at a very large distance from the lens.
(1 mark)
B What lens focal length would be appropriate to photograph objects 70.0 cm from
the lens?
(2
marks)
6
A Calculate the critical angle for light going from glass to air given that the glass
has a refractive index of 1.50.
(2 marks)
B The glass is used to manufacture a 900, 450, 450 prism. On the diagram drawn
below, continue the path of the light ray, as it enters and emerges from the prism.
(2 marks)
C Draw a sketch showing how you could use two such prisms to construct a
periscope to see over a wall
(2 mark)
7
Convex mirrors are frequently used as shop security mirrors because they have a
larger field of view than plane mirrors of the same size. (This assumes that both
mirrors are viewed form the same distance.)
A Draw two sketches to illustrate the fact that the convex mirror would have the
larger field of view.
(2 marks)
B The advantage of a larger field of view is offset by one major disadvantage.
Describe the disadvantage.
(1 mark)
8
A convex lens is used to project a magnified image of a globe filament onto a
screen.
A Draw a ray diagram to illustrate the situation described above.
(2 marks)
B If the filament to screen distance is 2.00 m and the image is 10.0 times bigger
than the object, what is the focal length of the lens?
Hint: Find u and v first
(4 marks)
Formula and Data
Velocity of light in a vacuum c = 3.00 x 108 ms-1
Refractive index of air
na= 1.00