Question 1

Suppose an object is placed 6.0 cm in front of a lens that has a focal length of 4.0 cm.Where is the image located? What are the magnification and the character of the image?

Accepted Answer

12 cm beyond the 4.0 cm lens, M = -2.0, the image is real and inverted

Question 2

A clown 2 m tall looks at himself in a full-length mirror (floor-to-ceiling).Where in the mirror must he look to see his feet?

Accepted Answer

A) 1 m from the floor 
B) 50 cm from the floor 
C) 25 cm from the floor 
D) at the bottom of the mirror 
E) 1.5 m from the floor 
A) 1 m from the floor 
B) 50 cm from the floor 
C) 25 cm from the floor 
D) at the bottom of the mirror 
E) 1.5 m from the floor A

Question 3

The image of an object beneath the surface of a medium of refractive index n > 1 is seen in air by a person looking down on the surface.This image, formed by light rays leaving the flat refractive surface, is:

Accepted Answer

A) real and closer to the viewer than the object. 
B) virtual and closer to the viewer than the object. 
C) real and farther from the viewer than the object. 
D) virtual and farther from the viewer than the object. 
E) virtual and the same distance from the viewer as the object. 
A) real and closer to the viewer than the object. 
B) virtual and closer to the viewer than the object. 
C) real and farther from the viewer than the object. 
D) virtual and farther from the viewer than the object. 
E) virtual and the same distance from the viewer as the object. B

Question 4

The inhabitants of a planet in another galaxy have their eyes at the exact centre of their 4.0-m long bodies.How long must a plane mirror be for such a creature to be able to see all of its body in the mirror?

Accepted Answer

A) 1.0 m 
B) 2.0 m 
C) 2.5 m 
D) 4.0 m 
E) 8.0 m 
A) 1.0 m 
B) 2.0 m 
C) 2.5 m 
D) 4.0 m 
E) 8.0 m

Question 5

An object is placed 10 cm in front of a concave mirror with a 20-cm focal length.Determine the image location (in cm).

Accepted Answer

A) (-20) 
B) (-15) 
C) (-10) 
D) (-5) 
E) 6.7 
A) (-20) 
B) (-15) 
C) (-10) 
D) (-5) 
E) 6.7

Question 6

An object is placed 25 cm in front of a lens of focal length 20 cm.60 cm past the first lens is a second lens of focal length 25 cm.What is the resulting magnification of the object in this setup?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 7

A concave mirror has a radius of curvature of 1.0 m.An object is placed 2.0 m in front of the mirror.Determine the location of the image (in cm).

Accepted Answer

A) 130 
B) 83 
C) 67 
D) 150 
E) 200 
A) 130 
B) 83 
C) 67 
D) 150 
E) 200

Question 8

An object 50-cm high is placed 1.0 m in front of a converging lens whose focal length is 1.5 m.Determine the image height (in cm).

Accepted Answer

A) 77 
B) 150 
C) 52 
D) 17 
E) 83 
A) 77 
B) 150 
C) 52 
D) 17 
E) 83

Question 9

A girl is sitting on the edge of a pier with her legs dangling over the water.Her soles are 80.0 cm above the surface of the water.A boy in the water looks up at her feet and wants to touch them with a reed.(nwater = 1.333.) He will see her soles as being:

Accepted Answer

A) right at the water surface. 
B) 53.3 cm above the water surface. 
C) exactly 80.0 cm above the water surface. 
D) 107 cm above the water surface. 
E) an infinite distance above the water surface. 
A) right at the water surface. 
B) 53.3 cm above the water surface. 
C) exactly 80.0 cm above the water surface. 
D) 107 cm above the water surface. 
E) an infinite distance above the water surface.

Question 10

A 10-cm focal length converging lens is used to magnify small newspaper print 2.0 mm high.Calculate the height of the image (in mm) for the maximum magnification for a normal eye.

Accepted Answer

A) 3.5 
B) 7.0 
C) 9.2 
D) 12 
E) 2.5 
A) 3.5 
B) 7.0 
C) 9.2 
D) 12 
E) 2.5

Question 11

Bottles of perfume sometimes have thick glass (n = 1.5) walls which give the impression the volume is larger than it is.Assume a cylindrical bottle has an inner radius of 1.0 cm and an outer radius of 2.0 cm.How thick (in cm) would the wall appear if you could see a mark on the inside surface?

Accepted Answer

A) 0.80 
B) 0.51 
C) 0.72 
D) 80 
E) 12 
A) 0.80 
B) 0.51 
C) 0.72 
D) 80 
E) 12

Question 12

An object 20-cm high is placed 50.0 cm in front of a lens whose focal length is 5.00 cm.Where will the image be located (in cm)?

Accepted Answer

A) 5.13 
B) 5.56 
C) 5.72 
D) 5.93 
E) 4.55 
A) 5.13 
B) 5.56 
C) 5.72 
D) 5.93 
E) 4.55

Question 13

A compound microscope is made with an objective lens (f0 = 0.900 cm) and an eyepiece (fe = 1.10 cm).The lenses are separated by a distance of 10.0 cm.What is the angular magnification? (Assume the near point is 25.0 cm.)

Accepted Answer

A) (-253) 
B) (-450) 
C) (-770) 
D) (-980) 
E) (-635) 
A) (-253) 
B) (-450) 
C) (-770) 
D) (-980) 
E) (-635)

Question 14

If a convex lens were made out of very thin clear plastic filled with air, and were then placed underwater where n = 1.33 and where the lens would have an effective index of refraction n = 1, the lens would act in the same way:

Accepted Answer

A) as a concave mirror in air. 
B) as a concave lens in air. 
C) as a convex lens in air. 
D) as a flat refracting surface between water and air as seen from the water side. 
E) as the glasses worn by a farsighted person. 
A) as a concave mirror in air. 
B) as a concave lens in air. 
C) as a convex lens in air. 
D) as a flat refracting surface between water and air as seen from the water side. 
E) as the glasses worn by a farsighted person.

Question 15

A far-sighted student has a near point of 1.0 m.Calculate the focal length (in cm) of the glasses needed so the near point will be normal (25 cm).

Accepted Answer

A) 72 
B) 25 
C) 33 
D) 100 
E) (-33) 
A) 72 
B) 25 
C) 33 
D) 100 
E) (-33)

Question 16

Which ray diagram is correct? The three rays in each diagram are distinguished by different types of lines.Hint: Check the behaviour of each ray as it interacts with the lens.

Accepted Answer

A) A 
B) B 
C) C 
D) D 
E) E 
A) A 
B) B 
C) C 
D) D 
E) E

Question 17

A convex mirror has a focal length of -20 cm.What is the object distance if the image distance is -10 cm?

Accepted Answer

A) 10 cm 
B) 40 cm 
C) 60 cm 
D) 20 cm 
E) 30 cm 
A) 10 cm 
B) 40 cm 
C) 60 cm 
D) 20 cm 
E) 30 cm

Question 18

A concave mirror has a focal length of 20 cm.What is the magnification if the object and image distances are 10 cm and -20 cm respectively?

Accepted Answer

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

Question 19

A convex mirror has a focal length of -20 cm.What is the position of the resulting image (in cm) if the image is upright and four times smaller than the object?

Accepted Answer

A) (-100) 
B) (-25) 
C) (-50) 
D) (-15) 
E) (-10) 
A) (-100) 
B) (-25) 
C) (-50) 
D) (-15) 
E) (-10)

Question 20

Which ray diagrams are correct? The three rays in each diagram are distinguished by different types of lines.Hint: Check the behaviour of each ray as it interacts with the lens.

Accepted Answer

A) B and C 
B) C and D 
C) D and E 
D) C and E 
E) C, D and E 
A) B and C 
B) C and D 
C) D and E 
D) C and E 
E) C, D and E

Exam 14: Image Formation

Suppose an object is placed 6.0 cm in front of a lens that has a focal length of 4.0 cm.Where is the image located? What are the magnification and the character of the image?

A clown 2 m tall looks at himself in a full-length mirror (floor-to-ceiling).Where in the mirror must he look to see his feet?

The image of an object beneath the surface of a medium of refractive index n > 1 is seen in air by a person looking down on the surface.This image, formed by light rays leaving the flat refractive surface, is:

The inhabitants of a planet in another galaxy have their eyes at the exact centre of their 4.0-m long bodies.How long must a plane mirror be for such a creature to be able to see all of its body in the mirror?

An object is placed 10 cm in front of a concave mirror with a 20-cm focal length.Determine the image location (in cm).

An object is placed 25 cm in front of a lens of focal length 20 cm.60 cm past the first lens is a second lens of focal length 25 cm.What is the resulting magnification of the object in this setup?

A concave mirror has a radius of curvature of 1.0 m.An object is placed 2.0 m in front of the mirror.Determine the location of the image (in cm).

An object 50-cm high is placed 1.0 m in front of a converging lens whose focal length is 1.5 m.Determine the image height (in cm).

A girl is sitting on the edge of a pier with her legs dangling over the water.Her soles are 80.0 cm above the surface of the water.A boy in the water looks up at her feet and wants to touch them with a reed.(nwater = 1.333.) He will see her soles as being:

A 10-cm focal length converging lens is used to magnify small newspaper print 2.0 mm high.Calculate the height of the image (in mm) for the maximum magnification for a normal eye.

Bottles of perfume sometimes have thick glass (n = 1.5) walls which give the impression the volume is larger than it is.Assume a cylindrical bottle has an inner radius of 1.0 cm and an outer radius of 2.0 cm.How thick (in cm) would the wall appear if you could see a mark on the inside surface?

An object 20-cm high is placed 50.0 cm in front of a lens whose focal length is 5.00 cm.Where will the image be located (in cm)?

A compound microscope is made with an objective lens (f0 = 0.900 cm) and an eyepiece (fe = 1.10 cm).The lenses are separated by a distance of 10.0 cm.What is the angular magnification? (Assume the near point is 25.0 cm.)

If a convex lens were made out of very thin clear plastic filled with air, and were then placed underwater where n = 1.33 and where the lens would have an effective index of refraction n = 1, the lens would act in the same way:

A far-sighted student has a near point of 1.0 m.Calculate the focal length (in cm) of the glasses needed so the near point will be normal (25 cm).

Which ray diagram is correct? The three rays in each diagram are distinguished by different types of lines.Hint: Check the behaviour of each ray as it interacts with the lens.

A convex mirror has a focal length of -20 cm.What is the object distance if the image distance is -10 cm?

A concave mirror has a focal length of 20 cm.What is the magnification if the object and image distances are 10 cm and -20 cm respectively?

A convex mirror has a focal length of -20 cm.What is the position of the resulting image (in cm) if the image is upright and four times smaller than the object?

Which ray diagrams are correct? The three rays in each diagram are distinguished by different types of lines.Hint: Check the behaviour of each ray as it interacts with the lens.

Electric Fields

Gausss Law

Electric Potential

Energy and Capacitance

Current and Resistance

Direct-Current Circuits

Magnetic Fields

Magnetic Forces

Faradays Law

Inductance

Alternating-Current Circuits

Electromagnetic Waves

The Nature of Light and the Principles of Ray Optics

Wave Optics

Diffraction Patterns and Polarisation

Quantisation and Wave-Particle Duality

Introduction to Quantum Mechanics

Atomic Physics

Quantum Physics of Molecules and Solids

Nuclei and Radioactivity

Particle Physics

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