Deck 18: Images

Question 1

A ball is held 50 cm in front of a plane mirror. The distance between the ball and its image is:

A) 100 cm
B) 150 cm
C) 200 cm
D) zero
E) 50 cm

Answer 1

100 cm

Question 2

A plane mirror is in a vertical plane and is rotating about a vertical axis at 100 rpm. A horizontal beam of light is incident on the mirror. The reflected beam will rotate at:

A) 100 rpm
B) 141 rpm
C) zero rpm
D) 200 rpm
E) 10,000 rpm

Answer 2

200 rpm

Question 3

A parallel beam of monochromatic light in air is incident on a plane glass surface. In the glass, the beam:

A) remains parallel
B) undergoes dispersion
C) becomes diverging
D) follows a parabolic path
E) becomes converging

Answer 3

remains parallel

Question 4

The focal length of a spherical mirror is N times its radius of curvature where N is:

A) 1/4
B) 1/2
C) 1
D) 2
E) 4

Question 5

A concave mirror forms a real image which is twice the size of the object. If the object is 20 cm from the mirror, the radius of curvature of the mirror must be about:

A) 13 cm
B) 20 cm
C) 27 cm
D) 40 cm
E) 80 cm

Question 6

A man stands with his nose 8 cm from a concave shaving mirror of radius 32 cm. The distance from the mirror to the image of his nose is:

A) 8 cm
B) 12 cm
C) 16 cm
D) 24 cm
E) 32 cm

Question 7

An erect object placed outside the focal point of a converging lens will produce an image that is:

A) erect and virtual
B) inverted and virtual
C) erect and real
D) inverted and real
E) impossible to locate

Question 8

Let p denote the object-lens distance and i the image-lens distance. The image produced by a lens of focal length f has a height that can be obtained from the object height by multiplying it by:

A) p/i
B) i/p
C) f/p
D) f/i
E) i/f

Question 9

A camera with a lens of focal length 6.0 cm takes a picture of a 1.4-m man standing 11 m away. The height of the image is about:

A) 0.39 cm
B) 0.77 cm
C) 1.5 cm
D) 3.0 cm
E) 6.0 cm

Question 10

An erect object is 2f in front of a convex lens of focal length f. The image is:

A) real, inverted, magnified
B) real, erect, same size
C) real, inverted, same size
D) virtual, inverted, reduced
E) real, inverted, reduced

Question 11

A 3-cm high object is in front of a thin lens. The object distance is 4 cm and the image distance is -8 cm. The image height is:

A) 0.5 cm
B) 1 cm
C) 1.5 cm
D) 6 cm
E) 24 cm

Question 12

In a cinema, a picture 2.5 cm wide on the film is projected to an image 3.0 m wide on a screen which is 18 m away. The focal length of the lens is about:

A) 7.5 cm
B) 10 cm
C) 12.5 cm
D) 15 cm
E) 20 cm

Question 13

An ordinary magnifying glass in front of an erect object produces an image that is:

A) real and erect
B) real and inverted
C) virtual and inverted
D) virtual and erect
E) none of these

Question 14

Consider the following four statements concerning a compound microscope:
I. Each lens produces an image that is virtual and inverted.
II. The objective lens has a very short focal length.
III. The eyepiece is used as a simple magnifying glass.
IV. The objective lens is convex and the eyepiece is concave.
Which two of the four statements are correct?

A) I, II
B) I, III
C) I, IV
D) II, III
E) II, IV

Question 15

A magnifying glass has a focal length of 15 cm. If the near point of the eye is 25 cm from the eye the angular magnification of the glass is about:

A) 0.067
B) 0.33
C) 0.67
D) 1.7
E) .5

Question 16

A converging lens of focal length 20 cm is placed in contact with a diverging lens of focal length 30 cm. The focal length of this combination is:

A) +60 cm
B) +25 cm
C) +12 cm
D) -10 cm
E) +10 cm

Question 17

In a two lens microscope, the intermediate image is:

A) virtual, erect and magnified
B) real, erect and magnified
C) real, inverted and magnified
D) virtual, inverted and reduced
E) virtual, inverted and magnified