Question 1

The corrective lenses of a person suffering from which of the following vision ailments could be used to start a fire by focusing sunlight?

Accepted Answer

A)  myopia 
B)  no eyeglass lenses can be used to make a fire 
C)  astigmatism 
D)  hyperopia 
E)  cataracts 
A)  myopia 
B)  no eyeglass lenses can be used to make a fire 
C)  astigmatism 
D)  hyperopia 
E)  cataracts

Question 2

For maximum angular magnification in a compound microscope, the objective focal length (fo) and the eyepiece focal length (fe) should be chosen so that

Accepted Answer

A)  fo and fe are both the largest available. 
B)  fo and fe are both the smallest available. 
C)  fo is the smallest available; fe is the largest available. 
D)  fo is the largest available; fe is the smallest available. 
E)  fo and fe are about the same. 
A)  fo and fe are both the largest available. 
B)  fo and fe are both the smallest available. 
C)  fo is the smallest available; fe is the largest available. 
D)  fo is the largest available; fe is the smallest available. 
E)  fo and fe are about the same.

Question 3

A pinhole camera is used to produce an image of a bird that is 3.8 m away. If the size of the bird's image on the screen is 3.0% of the size of the bird, what is the distance from pinhole to screen?

Accepted Answer

A)  5.7 cm 
B)  23 cm 
C)  11 cm 
D)  impossible to determine given the information. 
A)  5.7 cm 
B)  23 cm 
C)  11 cm 
D)  impossible to determine given the information.

Question 4

How is chromatic aberration corrected in large astronomical reflecting telescopes?

Accepted Answer

A)  a combination of lenses designed to cancel the aberrations 
B)  use a parabolic mirror instead of a spherical mirror 
C)  a reflecting telescope has no chromatic aberration 
D)  change the resolution of the telescope 
A)  a combination of lenses designed to cancel the aberrations 
B)  use a parabolic mirror instead of a spherical mirror 
C)  a reflecting telescope has no chromatic aberration 
D)  change the resolution of the telescope

Question 5

A 50.0 mm lens is used to take a picture of an object 1.30 m tall located 4.00 m away. What is the height of the image on the film?

Accepted Answer

A)  21.0 mm 
B)  16.5 mm 
C)  12.0 mm 
D)  10.5 mm 
E)  9.20 mm 
A)  21.0 mm 
B)  16.5 mm 
C)  12.0 mm 
D)  10.5 mm 
E)  9.20 mm

Question 6

What kind of lenses are used in a compound microscope?

Accepted Answer

A)  The objective is converging; the eyepiece is diverging. 
B)  The objective is diverging; the eyepiece is converging. 
C)  The objective and eyepiece are both diverging. 
D)  The objective and eyepiece are both converging. 
A)  The objective is converging; the eyepiece is diverging. 
B)  The objective is diverging; the eyepiece is converging. 
C)  The objective and eyepiece are both diverging. 
D)  The objective and eyepiece are both converging.

Question 7

Two lenses with refractive powers of 10 D and 15 D are placed in contact. What is the refractive power of the combination?

Accepted Answer

A)  15 D 
B)  25 D 
C)  0.67 D 
D)  5.0 D 
E)  1.5 D 
A)  15 D 
B)  25 D 
C)  0.67 D 
D)  5.0 D 
E)  1.5 D

Question 8

The refractive power of a lens of focal length 40 cm is

Accepted Answer

A)  4.0 D. 
B)  0.40 D. 
C)  2.5 D. 
D)  −2.5 D. 
E)  0.16 D. 
A)  4.0 D. 
B)  0.40 D. 
C)  2.5 D. 
D)  −2.5 D. 
E)  0.16 D.

Question 9

Two lenses, the first with focal length 10.0 cm and the second with focal length −12.5 cm, are separated by 20.0 cm. An object of height 2.40 cm is placed 15.0 cm in front of the first lens. Which of the following characteristics does the final image have?

Accepted Answer

A)  real and upright 
B)  real and inverted 
C)  virtual and upright 
D)  virtual and inverted 
E)  virtual and diminished in size 
A)  real and upright 
B)  real and inverted 
C)  virtual and upright 
D)  virtual and inverted 
E)  virtual and diminished in size

Question 10

An astronomical telescope is made with lenses of focal lengths 80.0 and 1.25 cm. What magnifying power does this telescope provide?

Accepted Answer

A)  10 
B)  81 
C)  79 
D)  64 
E)  41 
A)  10 
B)  81 
C)  79 
D)  64 
E)  41

Question 11

An astronomical telescope is made with lenses of focal lengths 80.0 cm and 2.00 cm. Two stars in the sky are separated by 0.080°. What angle of separation do they have when viewed in the telescope?

Accepted Answer

A)  40° 
B)  6.4° 
C)  3.2° 
D)  1.6° 
E)  0.080° 
A)  40° 
B)  6.4° 
C)  3.2° 
D)  1.6° 
E)  0.080°

Question 12

A small object has an angular diameter of 0.50°. When viewed through a magnifier, it has an angular diameter of 8.0°. What is the angular magnification in this case?

Accepted Answer

A)  4.0 
B)  8.0 
C)  16 
D)  32 
E)  8.5 
A)  4.0 
B)  8.0 
C)  16 
D)  32 
E)  8.5

Question 13

A telescope is set up in an introductory physics lab using lenses of focal lengths 10 cm and 50 cm. Since both lenses are the same diameter, it is not immediately clear which one to use as the eyepiece and which to use as the objective. If one uses the lens with a 50 cm focal length as the eyepiece, what power results?

Accepted Answer

A)  500 
B)  5 
C)  0.2 
D)  0.002 
E)  one cannot look through the system in this direction 
A)  500 
B)  5 
C)  0.2 
D)  0.002 
E)  one cannot look through the system in this direction

Question 14

An astronomical telescope is made with lenses of focal lengths 80.0 and 2.00 cm. What is the barrel length of this telescope?

Accepted Answer

A)  80.0 cm 
B)  82.0 cm 
C)  78.0 cm 
D)  105 cm 
E)  127 cm 
A)  80.0 cm 
B)  82.0 cm 
C)  78.0 cm 
D)  105 cm 
E)  127 cm

Question 15

A farsighted person cannot see clearly closer than 2.0 m. What power contact lenses would correct this near point to 25 cm?

Accepted Answer

A)  2.0 D 
B)  0.5 D 
C)  −0.5 D 
D)  3.5 D 
E)  −3.5 D 
A)  2.0 D 
B)  0.5 D 
C)  −0.5 D 
D)  3.5 D 
E)  −3.5 D

Question 16

You use a camera with a lens of focal length 50.0 mm to take a picture of a 2.50 m tall statue located 7.20 m away. If the image height on the film is 18.2 mm, what is the distance from the lens to the film?

Accepted Answer

A)  5.04 cm 
B)  need more information 
C)  6.32 mm 
D)  5.24 cm 
A)  5.04 cm 
B)  need more information 
C)  6.32 mm 
D)  5.24 cm

Question 17

The lens of a slide projector has a focal length of 10.0 cm. It is used to project the image of a 35 mm slide (24 mm × 36 mm) onto a square screen located 6.0 m away. Of the following screen widths, which is the smallest that would allow the entire image to fit?

Accepted Answer

A)  5.1 m 
B)  4.4 m 
C)  2.2 m 
D)  1.1 m 
E)  0.88 m 
A)  5.1 m 
B)  4.4 m 
C)  2.2 m 
D)  1.1 m 
E)  0.88 m

Question 18

An astronomical telescope has a magnifying power of 100 when using a 2.00 cm focal length eyepiece. How long is the barrel of the telescope?

Accepted Answer

A)  52.0 cm 
B)  100 cm 
C)  102 cm 
D)  200 cm 
E)  202 cm 
A)  52.0 cm 
B)  100 cm 
C)  102 cm 
D)  200 cm 
E)  202 cm

Question 19

A 5.0 cm focal length lens is used as a magnifier. Assuming a near point of 25 cm, about what magnification is attained?

Accepted Answer

A)  25 
B)  10 
C)  60 
D)  1.2 
E)  5 
A)  25 
B)  10 
C)  60 
D)  1.2 
E)  5

Question 20

Which of the following is not necessarily true about the image produced by a pinhole camera?

Accepted Answer

A)  The image is inverted. 
B)  The image is smaller than the object. 
C)  The image is real. 
D)  None of the answer choices are correct. 
A)  The image is inverted. 
B)  The image is smaller than the object. 
C)  The image is real. 
D)  None of the answer choices are correct.

Exam 24: Optical Instruments

The corrective lenses of a person suffering from which of the following vision ailments could be used to start a fire by focusing sunlight?

For maximum angular magnification in a compound microscope, the objective focal length (fo) and the eyepiece focal length (fe) should be chosen so that

A pinhole camera is used to produce an image of a bird that is 3.8 m away. If the size of the bird's image on the screen is 3.0% of the size of the bird, what is the distance from pinhole to screen?

How is chromatic aberration corrected in large astronomical reflecting telescopes?

A 50.0 mm lens is used to take a picture of an object 1.30 m tall located 4.00 m away. What is the height of the image on the film?

What kind of lenses are used in a compound microscope?

Two lenses with refractive powers of 10 D and 15 D are placed in contact. What is the refractive power of the combination?

The refractive power of a lens of focal length 40 cm is

Two lenses, the first with focal length 10.0 cm and the second with focal length −12.5 cm, are separated by 20.0 cm. An object of height 2.40 cm is placed 15.0 cm in front of the first lens. Which of the following characteristics does the final image have?

An astronomical telescope is made with lenses of focal lengths 80.0 and 1.25 cm. What magnifying power does this telescope provide?

An astronomical telescope is made with lenses of focal lengths 80.0 cm and 2.00 cm. Two stars in the sky are separated by 0.080°. What angle of separation do they have when viewed in the telescope?

A small object has an angular diameter of 0.50°. When viewed through a magnifier, it has an angular diameter of 8.0°. What is the angular magnification in this case?

An astronomical telescope is made with lenses of focal lengths 80.0 and 2.00 cm. What is the barrel length of this telescope?

A farsighted person cannot see clearly closer than 2.0 m. What power contact lenses would correct this near point to 25 cm?

You use a camera with a lens of focal length 50.0 mm to take a picture of a 2.50 m tall statue located 7.20 m away. If the image height on the film is 18.2 mm, what is the distance from the lens to the film?

The lens of a slide projector has a focal length of 10.0 cm. It is used to project the image of a 35 mm slide (24 mm × 36 mm) onto a square screen located 6.0 m away. Of the following screen widths, which is the smallest that would allow the entire image to fit?

An astronomical telescope has a magnifying power of 100 when using a 2.00 cm focal length eyepiece. How long is the barrel of the telescope?

A 5.0 cm focal length lens is used as a magnifier. Assuming a near point of 25 cm, about what magnification is attained?

Which of the following is not necessarily true about the image produced by a pinhole camera?

Introduction

Motion Along a Line

Motion in a Plane

Force and Newtons Laws of Motion

Circular Motion

Conservation of Energy

Linear Momentum

Torque and Angular Momentum

Fluids

Elasticity and Oscillations

Waves

Sound

Temperature and the Ideal Gas

Heat

Thermodynamics

Electric Forces and Fields

Electric Potential

Electric Current and Circuits

Magnetic Forces and Fields

Electromagnetic Induction

Alternating Current

Electromagnetic Waves

Reflection and Refraction of Light

Interference and Diffraction

Relativity

Early Quantum Physics and the Photon

Quantum Physics

Nuclear Physics

Particle Physics

Filters

For maximum angular magnification in a compound microscope, the objective focal length (f_o) and the eyepiece focal length (f_e) should be chosen so that