Download You want to project a real image of an object using

Physics 534 – Lenses & Mirrors
Name:
Lenses & Mirrors – Assignment
1.
A 12 cm tall object is placed in front of a concave mirror. The focal length is 30 cm. The
object is located 70 cm from the top of the mirror.
What will be the height of the image reflected by the mirror?
2.
A lighted object is placed in front of a concave mirror, as illustrated below. Draw a ray
diagram to determine the position of the image.
Object
F
3.
An object, 45.0 cm high, is placed in front of a convex mirror. A virtual image, 15.0 cm
high, is formed. The focal length of the mirror is -30.0 cm. At what distance is the object
from the mirror?
A)
20.0 cm
C)
90.0 cm
B)
60.0 cm
D)
120.0 cm
4.
A candle is placed in front of a mirror. The candle is located between the mirror and the
focal point of the mirror.
Focal point
Centre
Which statement correctly describes the image of the candle?
A)
The image is in front of the mirror, upright, real, and smaller than the object.
B)
The image is behind the mirror, upright, virtual, and larger than the object.
C)
The image is behind the mirror, upright, virtual, and smaller than the object.
D)
The image is in front of the mirror, inverted, real and smaller than the object.
5.
An object with a height of 6.00 cm is placed in front of a spherical, concave lens at
do = 30.00 cm. Its image forms at di = 20.00 cm. What is the height of the image?
A)
4.00 cm
C)
9.00 cm
B)
2.67 cm
D)
0.33 cm
6.
An object 1.5 cm high is placed 8.00 cm from a concave mirror having a focal length of
4.00 cm.
a)
What is the position of the image (di)?
b)
State 3 characteristics of this image.
c)
Calculate the size of the image.
7.
8.
You place an object 30 cm from a concave mirror. There is a real image 15 cm from the
mirror. Next, you move the object closer so it is 6.0 cm from the mirror. What is the new
position of the image?
A)
10 cm behind the mirror
B)
15 cm behind the mirror
C)
20 cm behind the mirror
D)
25 cm behind the mirror
You want to project a real image of an object using a concave mirror. This object is
placed below the principal axis of the mirror. The diagram below illustrates the situation.
F
C
Object
Locate and draw the image by means of the appropriate ray diagram.
9.
When an object is placed 10.0 cm in front of a converging lens, an image, 6.0 cm behind
the lens, appears on a screen. The object is subsequently moved 7.0 cm closer to the
lens.
What will be the magnification of the image after the move?
10.
A child’s toy consists of a small light bulb that lights a picture of Scooby Doo. The light
from this picture then passes through a convex lens and is projected on the wall. The
picture of Scooby Doo is 2.1 cm from the lens, and the focal length of the lens is 2.0 cm.
The child holds the toy so that the image of Scooby Doo is perfectly focused on the wall.
At what distance is the lens from the wall?
11.
The incident rays I1, I2 and I3 strike the convex lens illustrated below.
1
I1
2
I2
3
I3
F
F
'
4
6
7
Which are the correct refracted rays?
A)
1, 5, 7
B)
2, 3, 4
C)
3, 4, 5
D)
4, 5, 6
5
12.
A manufacturer of slide projectors wants to produce images 1.5 m in height on a screen
that is placed 5.0 m from the lens of the projector. If the height of the slides is 30 mm,
calculate the focal length of the lens.
13.
To repair a microscope a technician needs a lens combination with a power of 5.0
dioptres. Which two of the following lenses could be used?
Lens A = fA = 10.0 cm
Lens B = fB = 15.0 cm
Lens C = fC = -5.0 cm
Lens D = fD = -20.0 cm
14. A lens system is made up of two lenses
cemented together. The focal lengths of these
lenses are 50 cm and -40 cm.
What is the optical power of this lens system?
A)
-0.50 dioptre
B)
0.10 dioptre
C)
4.5 dioptres
D)
10 dioptres
15.
Before performing a laboratory experiment, a student is asked to draw a diagram to show
the position of the image of an object produced by an optical instrument. Which one of
the following diagrams does NOT correspond to reality?
A)
F
B)
F
C)
F
F
D)
no image
F
16.
F
A converging lens has a focal length of 10 cm. A second lens is to be added to the first in
order to have a combined focal length of 20 cm. What must be the focal length of the
second lens?
17.
How far from a converging lens with a focal length of 10 cm must an object be placed in
order to form an upright image 5 times larger than the object?
18.
Anne wants to project the image of an object on a vertical screen using a converging lens
with a focal length of 50 cm. The inverted real image must be 4 times larger than the
object. How far from the object must she place the lens?
19.
An image must be projected onto a screen from a picture slide that is 3.50 cm high. The
focal length of the projector’s converging lens is 15.00 cm. The screen is placed 615 cm
away from the lens. What is the height of the projected image?
A)
0.088 cm
C)
140 cm
B)
144 cm
D)
147 cm
20.
A numismatist studies a rare coin and tries to determine the inscribed date using a
magnifying glass. He holds the coin 5.0 cm from the magnifying glass and reads the date
clearly, five times larger than the real coin. What is the focal length of the magnifying
glass?
21.
An insect is magnified four times using a
magnifying glass (convex lens) with a focal length
of 19 cm.
At what distance from the magnifying glass is the
upright image of the insect formed?
22.
A system of three lenses is found to have a power of 15 diopters. Data for two of the
lenses is given below.
Lens
Focal Length (m)
A
0.05
B
0.20
C
?
Determine the focal length of lens C in metres.
23.
White light passes through a series of filters. First the light passes through a yellow filter
followed by a red filter. If a blue dress was view under this filtered light, what color would
it appear?
24.
White light passes through a green filter, then trough a blue filter. This light shines onto a
white wall.
Another beam of white light passes through a yellow filter then through a green filter.
This light shines onto the same spot of the wall.
What color will the spot of the wall appear?
25.
A laser beam guided by an optical fibre is used to transmit information. This fibre is
made of a transparent substance coated with a transparent sheath. The refractive index
of the transparent substance is n1 and the refractive index of the transparent sheath is n2.
Path of a Laser Beam in an Optical Fibre
Transparent Substance, n1
Laser Beam
Transparent Sheath, n2
Light Detector
Laser
What condition must be satisfied for the laser beam to remain inside the optical fibre?
A)
n1 = n2
C)
B)
n1 > n2
D)
n1 < n2
n1 =
1
n2
26.
The following diagrams illustrate light rays passing from air into different transparent
media at the same angle of incidence. Which diagram illustrates the ray entering the
medium with the greatest optical density?
A)
C)
Air
Air
Transparent Medium
Transparent Medium
B)
D)
Air
Air
Transparent Medium
Transparent Medium
27.
A fish sees an insect on the surface of a calm lake. One of the light rays allowing the fish
to see the insect is illustrated below.
Air

Water
The refractive index of the lake is 1.35 and the refractive index of the air is 1.00. What is
the size of the angle  formed by the refracted light ray and the surface of the lake?
28.
In a laboratory experiment, a beam of light enters an aquarium filled with water. The
diagram shows the path of the light from the aquarium glass into the water.
Water
n = 1.33
35°
Glass
30°
Given the data in the diagram, what angle of incidence will permit the light to enter the
water?
A)
< 62.5°
C)
62.5°
B)
> 62.5°
D)
90.0°
29.
In order to identify a transparent substance, Chris decides to find its index of refraction.
He shines a light ray on this substance. The following diagram illustrates part of his
experiment.
60°
nair = 1.00
27°
Unknown substance
Given the results shown in the diagram above, what is the index of refraction of the
unknown substance?
A)
0.52
C)
1.9
B)
1.1
D)
2.2
30.
In the laboratory, light rays are observed as they pass through different transparent
mediums with different indices of refraction. The angle of incidence entering each
medium is the same.
30°
30°
Medium1
n1
30°
Medium 2
n2
Medium 3
n3
According to the diagrams above, which of the following is correct?
A)
n1 > n 2 > n 3
C)
n1 < n 3 < n 2
B)
n1 < n 2 < n 3
D)
n2 > n 1 > n 3
31.
Light travels from flint glass (n = 1.65) into crown glass (n = 1.52). What is the critical
angle for flint glass in this situation?
A)
37.3°
C)
67.1°
B)
41.1°
D)
90.0°
32.
A coin lies on the bottom of a swimming pool under 1.2m of water and 1m form the edge
of the pool, as illustrated. A flashlight beam is directed over the edge of the pool to
illuminate the coin. At what angle relative to the pool wall must the flashlight be aimed?
33.
A light ray travelling from air into another
transparent substance makes an angle of
5
50°
the surface in the transparent substance.
Air (nair = 1.00)
60°
Transparent
substance
What is the index of refraction of the transparent substance?
PAST OPTIC QUESTIONS……………
34.
A plane mirror is placed vertically in the corner of a room. Steve and Lynn are playing
cards in this room. This situation is illustrated below.
Mirror
Steve’s Eye
Lynn’s Cards
Table
According to this diagram, can Steve see Lynn’s cards using the mirror? Explain your
answer by drawing the ray diagram that correctly shows Steve’s field of vision.
35.
Draw the field of view for each observer, O, & state whether they would be able to see
the object.
A)
B)
O
C

object
C

O
object