Deck 26: Relativity: Part A

Question 1

You are building a compound microscope with an objective lens of focal length 1.1 cm and an eyepiece lens of focal length 5.0 cm.You mount the lenses 18 cm apart.What is the approximate magnification of your microscope?

A) 3
B) 7
C) 80
D) 130

Answer 1

80

Question 2

Which of the following would decrease the magnification of a compound microscope?

A) Replacing the objective lens with one of larger diameter.
B) Replacing the eyepiece lens with one of shorter focal length.
C) Replacing the eyepiece lens with one of smaller diameter.
D) Replacing the objective lens with one of longer focal length.

Answer 2

Replacing the objective lens with one of longer focal length.

Question 3

A refracting astronomical telescope has objective and eyepiece lenses of focal lengths 38 cm and 0.40 cm,respectively.What is the angular magnification of this instrument?

A) 95
B) 50
C) 27
D) 19.6

Answer 3

95

Question 4

What is the magnitude of the approximate magnification of a compound microscope with objective and eyepiece focal lengths of 0.90 cm and 3.6 cm,respectively,and a separation between lenses of 20 cm?

A) 460
B) 12
C) 20
D) 150

Question 5

When using an eyepiece of focal length f,the Yerkes refracting telescope gives a magnification of 800.What focal length eyepiece would yield a magnification of 500?

A) (8/5)²f
B) (5/8)f
C) (8/5)f
D) (5/8)²f

Question 6

Increasing the focal length in a telephoto lens by a factor of nine,while keeping the aperture size constant,will change the f-number by what factor?

A) 1/3
B) 1/9
C) 9
D) 3

Question 7

A simple magnifier makes an image appear at the near point distance from the eye of the viewer (25 cm).What is the magnifying power of the magnifier if it is constructed of a lens of focal length of 6.3 cm? Do not use the approximation formula.

A) 5.0
B) 50
C) 1.2
D) 7.3

Question 8

Decreasing the aperture diameter of a camera lens by a factor of three will change the f-number by what factor?

A) 3
B) 9
C) 1/9
D) 1/3

Question 9

Doubling the aperture diameter of a camera lens will change the light intensity admitted to the film by what factor?

A) 4.0
B) 0.25
C) 0.50
D) 2.0

Question 10

A nearsighted person cannot see objects clearly beyond 50 cm (the far point).If the patient has no astigmatism and contact lenses are prescribed,what is the power of the lens required to correct the patient's vision?

A) −2.0 diopters
B) −3.3 diopters
C) −4.0 diopters
D) −5.0 diopters

Question 11

If a person is nearsighted the corrective lens will

A) take an object at the far point and form an image at 25 cm.
B) take an object at 25 cm and form an image at the far point.
C) take an object at infinity and form an image at the far point.
D) take an object at infinity and form an image at 25 cm.

Question 12

A camera lens is initially set at f/16 for a shutter speed of 1/30 s.If the amount of lighting on the subject is unchanged,and the lens is set at f/5.6,what is the proper shutter speed at this setting?

A) 1/8 s
B) 1/250 s
C) 1/500 s
D) 1/16 s

Question 13

What is the f-number of a camera lens that has an aperture-opening diameter of 0.20 cm and a focal length of 3.0 cm?

A) 10
B) 0.10
C) 15
D) 0.80

Question 14

The Palomar reflecting telescope has a parabolic mirror with an 80-m focal length.What is the magnification achieved when an eyepiece of focal length 5.0 cm is used?

A) 1200
B) 800
C) 3200
D) 1600

Question 15

A telescope has an objective lens with a focal length of 90 cm and an eyepiece of focal length 3.0 cm.What is the angular magnification of the telescope?

A) 180
B) 33
C) 60
D) 30

Question 16

A magnifying lens with a focal length of 10 cm has what maximum magnification? (Assume the near point is 25 cm).Do not use the approximation formula.

A) 3.5
B) 2.5
C) 7.1
D) 3.0

Question 17

A given individual is unable to see objects clearly when they are beyond 75 cm.What focal length contact lens should be used to correct this problem?

A) 75 cm
B) −75 cm
C) −100 cm
D) −33.3 cm

Question 18

The Yerkes refracting telescope has a 1-m diameter objective lens of focal length 20 m and an eyepiece of focal length 2.0 cm.What is the magnification of the planet Mars as seen through this telescope?

A) 800
B) 1000
C) 400
D) 200

Question 19

A lens with a focal length of 12 cm has what refractive power?

A) 5.0 diopters
B) 9.6 diopters
C) 6.7 diopters
D) 8.3 diopters

Question 20

You are designing contact lenses for someone whose near point is 43 cm.What focal length lens should you prescribe so that an object can be clearly seen when placed at 25 cm in front of the eye?

A) 43 cm
B) 18 cm
C) −15 cm
D) 60 cm

Question 21

A camera has a lens that has an adjustable film distance used for focusing purposes.When the object being photographed is at a very large distance,the distance from the lens to the film is 50.0 mm.What would be the lens-to-film distance for an in-focus object 2.00 m from the camera?

A) 66.7 mm
B) 40.0 mm
C) 51.3 mm
D) 48.8 mm

Question 22

A 1.5-m tall woman stands 5.0 m in front of a camera with a 8.0 cm focal length lens.What is the size of the image formed on film?

A) 2.4 cm
B) 0.60 cm
C) 1.9 cm
D) 1.2 cm

Question 23

I take two pictures of my dog Kaycee.I use the same film and level of illumination for both pictures,but I halve the f-number for the second picture.By what factor will the required time of exposure change if the film is to receive the same total light energy?

A) 4.0
B) 0.50
C) 2.0
D) 0.25

Question 24

Doubling the f-number of a camera lens will change the light intensity admitted to the film by what factor?

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

Question 25

A camera is used to photograph the full moon,which has an angular diameter of 0.51°.The image on the film is 2.5 mm in diameter.What is the focal length of the lens?

A) 6.3 mm
B) 280 mm
C) 13 mm
D) 450 mm

Question 26

A high f-number:

A) allows using a slower shutter speed.
B) causes more spherical aberration.
C) allows a larger depth of focus.
D) is not related to any of the above options.

Question 27

Halving the focal length of a telephoto lens,while holding aperture size constant,will change the light intensity admitted to the film by what factor?

A) 0.50
B) 2.0
C) 0.25
D) 4.0

Question 28

A pinhole camera is used to photograph a 23-cm tall object at a distance of 3.0 m,the image being projected on film at a distance of 46 cm from the pinhole.What are the height and orientation of the image?

A) 3.5 cm,upright
B) 3.5 cm,inverted
C) 12 cm,upright
D) 12 cm,inverted

Question 29

A camera has a lens of focal length 50 mm and an f-number of 4.0.What is the diameter of the lens?

A) 50 mm
B) 100 mm
C) 25 mm
D) 13 mm