Question 1

A concave mirror has a radius of 2.0 m. What is the refractive power of a lens of the same focal length as the mirror?

Accepted Answer

A)  0.50 D 
B)  1.0 D 
C)  2.0 D 
D)  0.75 D 
E)  −0.50 D 
A)  0.50 D 
B)  1.0 D 
C)  2.0 D 
D)  0.75 D 
E)  −0.50 D

Question 2

A nearsighted person has a far point of 33 cm. What focal length contact lens would allow her to see in the distance?

Accepted Answer

A)  33 cm 
B)  −33 cm 
C)  67 cm 
D)  −67 cm 
E)  3.0 m 
A)  33 cm 
B)  −33 cm 
C)  67 cm 
D)  −67 cm 
E)  3.0 m

Question 3

An astronomical telescope has a barrel length of 33 cm and an angular magnification of 10. What are the focal lengths of the objective and the eyepiece, respectively?

Accepted Answer

A)  0.3 m, 3 m 
B)  30 cm, 3 cm 
C)  20 cm, 13 cm 
D)  3 cm, 30 cm 
A)  0.3 m, 3 m 
B)  30 cm, 3 cm 
C)  20 cm, 13 cm 
D)  3 cm, 30 cm

Question 4

Two converging lenses, the first with focal length 25 cm and the second with focal length 20 cm, are separated by 30 cm. A 4.0 cm tall object is placed 50 cm in front of the first lens. Where is the final image?

Accepted Answer

A)  20 cm after the second lens 
B)  20 cm before the second lens 
C)  10 cm after the second lens 
D)  10 cm before the second lens 
E)  50 cm after the second lens 
A)  20 cm after the second lens 
B)  20 cm before the second lens 
C)  10 cm after the second lens 
D)  10 cm before the second lens 
E)  50 cm after the second lens

Question 5

The pupil of the eye controls

Accepted Answer

A)  the focal length of the eye. 
B)  the far point. 
C)  the near point. 
D)  the amount of light reaching the retina. 
E)  none of these 
A)  the focal length of the eye. 
B)  the far point. 
C)  the near point. 
D)  the amount of light reaching the retina. 
E)  none of these

Question 6

A camera with a 50.0 mm lens is designed to focus on objects at distances ranging from 1.00 m to infinity. How far must the lens be able to move, relative to the image sensor plane, to focus over this range?

Accepted Answer

A)  50.0 mm 
B)  52.6 mm 
C)  47.4 mm 
D)  5.30 mm 
E)  2.63 mm 
A)  50.0 mm 
B)  52.6 mm 
C)  47.4 mm 
D)  5.30 mm 
E)  2.63 mm

Question 7

Two lenses, the first with focal length −12.5 cm and the second with focal length 20.0 cm, are separated by 15.0 cm. If an object is placed 50.0 cm in front of the first lens, where is the final image formed?

Accepted Answer

A)  10.0 cm before the first lens 
B)  25.0 cm before the second lens 
C)  25.0 cm after the second lens 
D)  50.0 cm after the second lens 
E)  100 cm after the second lens 
A)  10.0 cm before the first lens 
B)  25.0 cm before the second lens 
C)  25.0 cm after the second lens 
D)  50.0 cm after the second lens 
E)  100 cm after the second lens

Question 8

To get the same exposure on the film when the aperture diameter of a camera lens is doubled, what change should be made in the shutter speed?

Accepted Answer

A)  It should be doubled. 
B)  It should be halved. 
C)  It should be quadrupled. 
D)  It should be quartered. 
E)  It should be reduced by a factor of 1.414. 
A)  It should be doubled. 
B)  It should be halved. 
C)  It should be quadrupled. 
D)  It should be quartered. 
E)  It should be reduced by a factor of 1.414.

Question 9

Reflecting telescopes may suffer from what kind of aberration(s)?

Accepted Answer

A)  spherical 
B)  chromatic 
C)  spherical and chromatic 
D)  cinematic 
E)  Brewster and parabolic 
A)  spherical 
B)  chromatic 
C)  spherical and chromatic 
D)  cinematic 
E)  Brewster and parabolic

Question 10

Two converging lenses, the first with focal length 10.0 cm and the second with focal length 20.0 cm, are separated by 40.0 cm. An object, 3.00 cm in height, is placed 30.0 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)  none of these choices are correct 
A)  real and upright 
B)  real and inverted 
C)  virtual and upright 
D)  virtual and inverted 
E)  none of these choices are correct

Question 11

Two converging lenses, the first with focal length 40 cm and the second with focal length 331/3 cm, are separated by 10.0 cm. An object of height 6.0 cm is placed 20.0 cm in front of the first lens. What are the size and orientation of the final image?

Accepted Answer

A)  6.0 cm, upright 
B)  6.0 cm, inverted 
C)  24 cm, upright 
D)  24 cm, inverted 
E)  1.5 cm, inverted 
A)  6.0 cm, upright 
B)  6.0 cm, inverted 
C)  24 cm, upright 
D)  24 cm, inverted 
E)  1.5 cm, inverted

Question 12

A compound microscope gives a magnification of 200 with an eyepiece of focal length 2.00 cm. If the eyepiece is replaced with an eyepiece of focal length 1.50 cm, what magnification results?

Accepted Answer

A)  150 
B)  133 
C)  89 
D)  267 
E)  300 
A)  150 
B)  133 
C)  89 
D)  267 
E)  300

Question 13

Two converging lenses, the first with focal length 10.0 cm and the second with focal length 20.0 cm, are separated by 40.0 cm. An object, 3.00 cm in height, is placed 30.0 cm in front of the first lens. What is the height of the final image?

Accepted Answer

A)  3.00 cm 
B)  1.50 cm 
C)  6.00 cm 
D)  12.0 cm 
E)  24.0 cm 
A)  3.00 cm 
B)  1.50 cm 
C)  6.00 cm 
D)  12.0 cm 
E)  24.0 cm

Question 14

Which statement below best explains why we are able to see details of a distant object more clearly when viewed through a telescope?

Accepted Answer

A)  The image formed by the telescope is larger than the object. 
B)  The image formed by the telescope subtends a larger angle at the eye than the object does. 
C)  The intermediate image formed by the objective lens is greatly magnified. 
D)  Both the objective and eyepiece form real images. 
A)  The image formed by the telescope is larger than the object. 
B)  The image formed by the telescope subtends a larger angle at the eye than the object does. 
C)  The intermediate image formed by the objective lens is greatly magnified. 
D)  Both the objective and eyepiece form real images.

Question 15

A lens has a refractive power of −1.50 D. What is its focal length?

Accepted Answer

A)  150 cm 
B)  −150 cm 
C)  66.7 cm 
D)  −66.7 cm 
E)  8.50 cm 
A)  150 cm 
B)  −150 cm 
C)  66.7 cm 
D)  −66.7 cm 
E)  8.50 cm

Question 16

A TEM is a nonoptical microscope. What does TEM stand for?

Accepted Answer

A)  transverse electron magnifier 
B)  telescopic emulation machine 
C)  triple emission magnifier 
D)  transmission electron microscope 
E)  none of these answers are correct 
A)  transverse electron magnifier 
B)  telescopic emulation machine 
C)  triple emission magnifier 
D)  transmission electron microscope 
E)  none of these answers are correct

Question 17

Two converging lenses, the first with focal length 25 cm and the second with focal length 20 cm, are separated by 30 cm. A 4.0 cm tall object is placed 50 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)  none of these choices are correct 
A)  real and upright 
B)  real and inverted 
C)  virtual and upright 
D)  virtual and inverted 
E)  none of these choices are correct

Question 18

The eye focuses by

Accepted Answer

A)  moving the lens. 
B)  moving the retina. 
C)  moving both the lens and the retina. 
D)  changing the focal length of the lens. 
E)  changing the index of refraction of the vitreous fluid. 
A)  moving the lens. 
B)  moving the retina. 
C)  moving both the lens and the retina. 
D)  changing the focal length of the lens. 
E)  changing the index of refraction of the vitreous fluid.

Question 19

A simple magnifier of refractive power 15.0 D is used to observe a beetle on a student's desk. Assume that the magnifier is held close to the student's eye. If the image of the beetle is formed at her near point of 25 cm, how far is the beetle from the magnifier?

Accepted Answer

A)  50 cm 
B)  9.1 cm 
C)  4.2 cm 
D)  5.3 cm 
A)  50 cm 
B)  9.1 cm 
C)  4.2 cm 
D)  5.3 cm

Question 20

Two converging lenses, the first with focal length 10.0 cm and the second with focal length 20.0 cm, are separated by 40.0 cm. An object, 3.00 cm in height, is placed 30.0 cm in front of the first lens. Where is the final image formed?

Accepted Answer

A)  11.1 cm after the second lens 
B)  100 cm after the second lens 
C)  45.0 cm after the second lens 
D)  5.00 cm after the second lens 
E)  5.00 cm before the second lens 
A)  11.1 cm after the second lens 
B)  100 cm after the second lens 
C)  45.0 cm after the second lens 
D)  5.00 cm after the second lens 
E)  5.00 cm before the second lens

Exam 24: Optical Instruments

A concave mirror has a radius of 2.0 m. What is the refractive power of a lens of the same focal length as the mirror?

A nearsighted person has a far point of 33 cm. What focal length contact lens would allow her to see in the distance?

An astronomical telescope has a barrel length of 33 cm and an angular magnification of 10. What are the focal lengths of the objective and the eyepiece, respectively?

Two converging lenses, the first with focal length 25 cm and the second with focal length 20 cm, are separated by 30 cm. A 4.0 cm tall object is placed 50 cm in front of the first lens. Where is the final image?

The pupil of the eye controls

A camera with a 50.0 mm lens is designed to focus on objects at distances ranging from 1.00 m to infinity. How far must the lens be able to move, relative to the image sensor plane, to focus over this range?

Two lenses, the first with focal length −12.5 cm and the second with focal length 20.0 cm, are separated by 15.0 cm. If an object is placed 50.0 cm in front of the first lens, where is the final image formed?

To get the same exposure on the film when the aperture diameter of a camera lens is doubled, what change should be made in the shutter speed?

Reflecting telescopes may suffer from what kind of aberration(s)?

Two converging lenses, the first with focal length 10.0 cm and the second with focal length 20.0 cm, are separated by 40.0 cm. An object, 3.00 cm in height, is placed 30.0 cm in front of the first lens. Which of the following characteristics does the final image have?

Two converging lenses, the first with focal length 40 cm and the second with focal length 331/3 cm, are separated by 10.0 cm. An object of height 6.0 cm is placed 20.0 cm in front of the first lens. What are the size and orientation of the final image?

A compound microscope gives a magnification of 200 with an eyepiece of focal length 2.00 cm. If the eyepiece is replaced with an eyepiece of focal length 1.50 cm, what magnification results?

Two converging lenses, the first with focal length 10.0 cm and the second with focal length 20.0 cm, are separated by 40.0 cm. An object, 3.00 cm in height, is placed 30.0 cm in front of the first lens. What is the height of the final image?

Which statement below best explains why we are able to see details of a distant object more clearly when viewed through a telescope?

A lens has a refractive power of −1.50 D. What is its focal length?

A TEM is a nonoptical microscope. What does TEM stand for?

Two converging lenses, the first with focal length 25 cm and the second with focal length 20 cm, are separated by 30 cm. A 4.0 cm tall object is placed 50 cm in front of the first lens. Which of the following characteristics does the final image have?

The eye focuses by

A simple magnifier of refractive power 15.0 D is used to observe a beetle on a student's desk. Assume that the magnifier is held close to the student's eye. If the image of the beetle is formed at her near point of 25 cm, how far is the beetle from the magnifier?

Two converging lenses, the first with focal length 10.0 cm and the second with focal length 20.0 cm, are separated by 40.0 cm. An object, 3.00 cm in height, is placed 30.0 cm in front of the first lens. Where is the final image formed?

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

Two converging lenses, the first with focal length 40 cm and the second with focal length 33¹/₃ cm, are separated by 10.0 cm. An object of height 6.0 cm is placed 20.0 cm in front of the first lens. What are the size and orientation of the final image?