Question 1

Three lenses, each of focal length 90 cm, are placed in contact. What is the focal length of the combination?

Accepted Answer

A)  27 cm 
B)  93 cm 
C)  1/30 cm 
D)  45 cm 
E)  30 cm 
A)  27 cm 
B)  93 cm 
C)  1/30 cm 
D)  45 cm 
E)  30 cm

Question 2

A lens of focal length 1500 mm is used to project an image of the Sun onto a screen. If the Sun subtends an angle of 0.50° in the sky, what is the diameter of the image on the screen?

Accepted Answer

A)  60 mm 
B)  30 mm 
C)  26 mm 
D)  6.5 mm 
E)  13 mm 
A)  60 mm 
B)  30 mm 
C)  26 mm 
D)  6.5 mm 
E)  13 mm

Question 3

The objective of an astronomical telescope has a focal length of 900 mm. The telescope has eyepieces of focal lengths 20 mm, 15 mm, and 10 mm. What is the largest magnification for this telescope?

Accepted Answer

A)  920 
B)  900 
C)  880 
D)  90 
E)  60 
A)  920 
B)  900 
C)  880 
D)  90 
E)  60

Question 4

What causes chromatic aberration?

Accepted Answer

A)  The index of refraction depends on the wavelength. 
B)  The outer edges of the lens produce a focus at a different point than the central rays. 
C)  The absorption of light in the glass depends on the wavelength. 
D)  The coefficient of reflection depends on the wavelength. 
A)  The index of refraction depends on the wavelength. 
B)  The outer edges of the lens produce a focus at a different point than the central rays. 
C)  The absorption of light in the glass depends on the wavelength. 
D)  The coefficient of reflection depends on the wavelength.

Question 5

In a Galilean telescope, the eyepiece is a diverging lens, while the objective lens is a converging lens. What is one advantage of this arrangement over a telescope that uses two converging lenses?

Accepted Answer

A)  The observed image is inverted. 
B)  The observed image subtends a larger angle than the object. 
C)  The observed image is upright. 
D)  The observed image is real. 
E)  The observed image is virtual. 
A)  The observed image is inverted. 
B)  The observed image subtends a larger angle than the object. 
C)  The observed image is upright. 
D)  The observed image is real. 
E)  The observed image is virtual.

Question 6

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. What is the height of the final image?

Accepted Answer

A)  4.0 cm 
B)  2.0 cm 
C)  8.0 cm 
D)  9.3 cm 
E)  1.0 cm 
A)  4.0 cm 
B)  2.0 cm 
C)  8.0 cm 
D)  9.3 cm 
E)  1.0 cm

Question 7

The image produced on the retina by the lens of the eye, when properly focused, is

Accepted Answer

A)  real and inverted. 
B)  virtual and inverted. 
C)  real and upright. 
D)  virtual and upright. 
A)  real and inverted. 
B)  virtual and inverted. 
C)  real and upright. 
D)  virtual and upright.

Question 8

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. Where is the final image?

Accepted Answer

A)  20.0 cm after the second lens 
B)  12.5 cm after the second lens 
C)  5.60 cm after the second lens 
D)  50.0 cm after the second lens 
E)  100 cm after the second lens 
A)  20.0 cm after the second lens 
B)  12.5 cm after the second lens 
C)  5.60 cm after the second lens 
D)  50.0 cm after the second lens 
E)  100 cm after the second lens

Three lenses, each of focal length 90 cm, are placed in contact. What is the focal length of the combination?

A lens of focal length 1500 mm is used to project an image of the Sun onto a screen. If the Sun subtends an angle of 0.50° in the sky, what is the diameter of the image on the screen?

The objective of an astronomical telescope has a focal length of 900 mm. The telescope has eyepieces of focal lengths 20 mm, 15 mm, and 10 mm. What is the largest magnification for this telescope?

What causes chromatic aberration?

In a Galilean telescope, the eyepiece is a diverging lens, while the objective lens is a converging lens. What is one advantage of this arrangement over a telescope that uses two converging lenses?

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. What is the height of the final image?

The image produced on the retina by the lens of the eye, when properly focused, 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. Where is the final image?

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

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Exam 24: Optical Instruments

Three lenses, each of focal length 90 cm, are placed in contact. What is the focal length of the combination?

A lens of focal length 1500 mm is used to project an image of the Sun onto a screen. If the Sun subtends an angle of 0.50° in the sky, what is the diameter of the image on the screen?

The objective of an astronomical telescope has a focal length of 900 mm. The telescope has eyepieces of focal lengths 20 mm, 15 mm, and 10 mm. What is the largest magnification for this telescope?

What causes chromatic aberration?

In a Galilean telescope, the eyepiece is a diverging lens, while the objective lens is a converging lens. What is one advantage of this arrangement over a telescope that uses two converging lenses?

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. What is the height of the final image?

The image produced on the retina by the lens of the eye, when properly focused, 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. Where is the final image?

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