Lab 1

Question 1

Determine the focal length of a convex mirror that produces an image that is 16.0 cm behind the mirror when the object is 28.5 cm from the mirror. 
A. 37.0
B. -37.0 
C. 36.5
D. -36.5
E. 10.2

Answer 1

-37.0

Question 2

One of the purposes of this lab was to measure the focal lengths of both diverging and converging lenses and the magnification of a converging lens.
True
False

Answer 2

True

Question 3

Determine the image height for a 5.00 cm tall object placed 30.0 cm from a concave mirror having a focal length of 10.0cm.

• 2.48
  2. 48
  3. 30
• 3.30
• 5.00

Answer 3

-2.48

Question 4

In the case of the object being at the focal point of a diverging or concave lens, the image (__) be formed on a screen.

sometimes can
cannot
always can

Answer 4

cannot

Question 5

An object is located infinitely far from a converging lens of a focal length 70.m. The image will be focused on the screen placed (\_\_) far from the lens.
140 m 
infinitely
70. m 
35 m 
none of the above: image is virtual

Answer 5

70. m

Question 6

In an experimental case an object 5cm tall is placed 25cm from a convex lens with focal length equal to 25cm. How tall will the image be?
5 cm
0.2 cm 
-5 cm 
2.5 cm
immeasurably large

Answer 6

Immeasurably large

Question 7

The real image is twice as far from the convex lens than the object is. Therefore, the image is (\_\_). 
twice as tall as the object and inverted
half as tall as the object
equal in height to object
immeasurably large
shorter than the object

Answer 7

twice as tall as the object and inverted

Question 8

A 20cm tall object has a 40cm tall virtual image. What is the magnification?
0.5
2
3
4

Answer 8

2

Question 9

If the virtual image is twice as far from the convex lens as the object is, then the image is \_\_).
twice as tall as object and erect
half as tall as object
equal in height to object 
immeasurably large
shorter then object

Answer 9

twice as tall as object and erect

Question 10

A concave mirror has a radius of curvature of 1.6 m. The focal length is 
0.80 m.
3.2 m.
32 cm.
none of the above

Answer 10

0.80 m.

Question 11

If your face is 36cm in front of a plane mirror, where is the image of your face located?

36cm in back of the mirror
18cm in front of the mirror
36cm below the mirror

Answer 11

36cm in back of the mirror

Question 12

A converging, or convex, lens
is thicker in the middle than at the edges
is thinner in the middle than at the edges
has a virtual focus but not a real focus
forms only images smaller than the object
has a flat shapt

Answer 12

is thicker in the middle than at the edges

Question 13

What is the nature of the image formed by a concave mirror, if the magnification produced by it is negative?
virtual and inverted
real and inverted
virtual and upright
none of the above

Answer 13

real and inverted

Question 14

In an experimental case the object is placed 48.0cm from a convex, or converging, lens with focal length equal to 36.0cm. In cm how far from the lens will the image be formed?
144 cm
20 cm 
20.4 cm 
48 cm
infinitely far

Answer 14

144 cm

Question 15

The line passing through the center of each surface of a lens and at right angle to it is called the optical (principal) axis. It is also the (\_\_).
axis of rotation 
axis of symmetry
axis of curvature
radius of curvature
typical ray's direction

Answer 15

axis of symmetry

Question 16

Given a converging lens; if an object (such as the Sun) is at an infinite distance then the focal length of the lens is equal to

infinity
zero
the image distance
the object distance
five

Answer 16

the image distance

Question 17

Which of the following is true?
~Only virtual images can be projected on a screen
~A light ray passing through the center of a converging lens will be bent to pass through a lens.
~A virtual image is formed where the rays from an object meet after passing through a lens.
~The image seen in a plane mirror is a virtual image. (Correct! The image seen in a plane mirror is a virtual image.)
~A virtual image is always upside down.

Answer 17

The image seen in a plane mirror is a virtual image.

Correct! The image seen in a plane mirror is a virtual image.

Question 18

Images created by convex mirrors are always

smaller than the object.
the same size as the object.
larger than the object.
none of the above.

Answer 18

smaller than the object.

Question 19

In your lab, when you used a convex lens with the object located at twice the focal length, the image formed was
~larger..inverted..virtual
~larger..erect..virtual
~smaller..erect..virtual
~larger..erect..real
~smaller..inverted..real

Answer 19

smaller..inverted..real

Question 20

If a diverging, or concave, lens is placed in contact with a converging, or convex, lens they act in conjunction as a focal distance F, and the following relation is true.
F = f1 + f2
1/F = 1/f1 +1/f2
F = (f1+f2)/(f1*f2)
F = f1*f2
F = f1/f2

Answer 20

1/F = 1/f1 + 1/f2

Question 21

Which type of mirror produces an image that is always erect, always the same height as the object, and always virtual?

Concave
Convex
Plane
None of the above

Answer 21

Plane

Question 22

The focal length f of a converging lens can be obtained experimentally by a direct measurement of an image distance i when object distance is much larger than o and f and therefore can be considered infinite.

True
False

Answer 22

True

Question 23

Given Newton’s lens equation: 1/f = 1/p + 1/i. The distance from the center of the lens to the position of an object located on the axis of the lens is represented by the symbol (__) while the distance from the center of the lens to the focus on the lens is the symbol (__).

i. .f
i. .p
p. .f
p. .i
f. .p

Answer 23

p..f

Question 24

Name the spherical mirror which can produce a real and diminished image of an object. 
Concave mirror
Convex mirror
Plane mirror
Dichroic mirror
Silvered mirror

Answer 24

Concave mirror

Question 25

``` Given Si = Image Size and So = Object Size. Also given that 1/f = 1/p + 1/i. The magnitude of a ratio Si/So is the same as the magnitude of a ratio p/i p/f i/f i/p f/i ```

Answer 25

i/p

Question 26

Which of the following is true? When used alone, converging lenses can form only real images. converging lenses can form only virtual images. converging lenses can form only inverted images. diverging lenses can form only real images. diverging lenses can form only virtual images.

Answer 26

diverging lenses can form only virtual images.

Question 27

Images formed by concave lenses are virtual. enlarged. none of the above. real and inverted.

Answer 27

virtual.

Question 28

The magnitude of the ratio of the size or height of the image to the size or height of the object is called ``` focal distance magnification radius of a lens symmetry focal ratio ```

Answer 28

magnification

Question 29

A diverging lens ``` is sometimes called a convex lens has a virtual focus but not a real focus focuses rays of light through a single point forms images on a screen has a real focus ```

Answer 29

has a virtual focus but not a real focus

Question 30

A diverging lens forms both real and virtual images. True False

Answer 30

Flase

Question 31

A real image can be formed on a screen while a virtual image cannot. In this lab you observed real images formed by converging lenses. True False

Answer 31

True

Question 32

When a converging lens is used as a magnifying glass, the image produced is ``` real and inverted. real and upright. virtual and inverted. virtual and upright. none of the above -- a converging lens cannot be used as a magnifying glass. ```

Answer 32

virtual and upright.

Question 33

An object is located infinitely far from a diverging lens of a virtual focal lens 23.0m. The image distance is (__). Hint: the image is virtual. ``` 46 m infinity 23.0 m -23.0 m -46.0 m ```

Answer 33

-23.0 m

Question 34

A diverging lens forms images that are ``` virtual and erect real and erect real and inverted virtual and inverted either real or virtual ```

Answer 34

Virtual and erect

Question 35

If an object is outside the focal point on a concave mirror, the image will be virtual and inverted. real and inverted. virtual and upright. none of the above.

Answer 35

real and inverted.

Question 36

One of the purposes of this lab was to study the lens equation which connects focal distance and object distance. True False

Answer 36

True

Question 37

A converging lens forms only real images while a diverging lens forms only virtual images. True False

Answer 37

False

Question 38

A convex, or converging, lens forms only real images while a concave, or diverging, lens forms only virtual images. True False

Answer 38

False

Question 39

In an experimental case the object is placed 50.cm from a converging lens with focal length equal to 25cm. What will be the magnification of the image? ``` 25 2.0 1.0 -1.0 infinity ```

Answer 39

-1.0

Question 40

``` A convex lens of focal length 50.cm is configured in conjunction with a concave lens of virtual focal length 50.cm. What will be the focal length of the optical system? 100 cm 75 cm 50 cm 25 cm infinity ```

Answer 40

infinity