Question 1

When a flower petal is 4.0 cm in front of a convex lens,the inverted image is half the height of the petal.What is the focal length of this lens?

Accepted Answer

A) 1.3 cm 
B) 2.0 cm 
C) 4.0 cm 
D) 5.3 cm 
A) 1.3 cm 
B) 2.0 cm 
C) 4.0 cm 
D) 5.3 cm A

Question 2

Mary builds a simple refracting telescope using two lenses of focal length 80 cm and 5.0 cm.The respective diameters are 60 mm and 10 mm.How many degrees wide does the moon appear through the telescope if it appears only 1/2 degree wide with the "naked eye"?

Accepted Answer

8° (16 times larger)

Question 3

When an object is placed 118 cm from a thin concave lens,its image is found to be 59 cm from the lens.The lens is removed,and replaced by a thin convex lens whose focal length has the same magnitude as the diverging lens.This second lens is at the original position of the first lens.Where is the image of the object now?

Accepted Answer

at infinity

Question 4

A slide projector is set up with its lens 6.0 m from the screen.The projected image on the screen is 1.5 m square for a slide (the object)that is 2.5 cm square.
(a)How far is the slide from the lens?
(b)What is the focal length of the projector lens?

Accepted Answer

The answer of A slide projector is set up with...

Question 5

A nearsighted person has a far point that is 4.2 m from his eyes.What power contact lenses must he wear to allow him to focus on distant mountains?

Accepted Answer

A) 0.48 diopters 
B) -0.48 diopters 
C) -0.36 diopters 
D) -0.24 diopters 
E) 0.24 diopters 
A) 0.48 diopters 
B) -0.48 diopters 
C) -0.36 diopters 
D) -0.24 diopters 
E) 0.24 diopters

Question 6

As a treatment for cataracts (a cloudiness of the lens of the eye),the natural lens is removed and a plastic lens is implanted.After this is done a person can see distant objects clearly,but he cannot accommodate to focus on nearby objects.If such a person wanted to read a book at a distance of 25 cm,he would have to wear contact lenses having a diopter power of

Accepted Answer

A) +2.78 diopters 
B) +3.33 diopters 
C) -1.78 diopters 
D) +4.00 diopters 
E) -4.00 diopters 
A) +2.78 diopters 
B) +3.33 diopters 
C) -1.78 diopters 
D) +4.00 diopters 
E) -4.00 diopters

Question 7

An object is 50 cm from a concave mirror of radius of curvature of magnitude 60 cm.How far is the image from the mirror?

Accepted Answer

A) 19 cm 
B) 35 cm 
C) 60 cm 
D) 75 cm 
E) 120 cm 
A) 19 cm 
B) 35 cm 
C) 60 cm 
D) 75 cm 
E) 120 cm

Question 8

A person's face is 30 cm in front of a concave spherical shaving mirror.If the image is an erect image that is 1.5 times as large as the object,what is the focal length mirror?

Accepted Answer

A) 20 cm 
B) 50 cm 
C) 70 cm 
D) 90 cm 
A) 20 cm 
B) 50 cm 
C) 70 cm 
D) 90 cm

Question 9

Alice is farsighted and cannot see objects clearly that are closer to her eye than 80.0 cm.What is the refractive power of the contact lenses that will enable her to comfortably see objects at a distance of 25.0 cm from her eyes?

Accepted Answer

A) +2.75 diopters 
B) -2.75 diopters 
C) -4.72 diopters 
D) +4.72 diopters 
E) +7.00 diopters 
A) +2.75 diopters 
B) -2.75 diopters 
C) -4.72 diopters 
D) +4.72 diopters 
E) +7.00 diopters

Question 10

A toy is 14 cm in front of a convex spherical mirror.If the image of the toy is 5.8 cm behind the mirror,what is the focal length of the mirror?

Accepted Answer

A) -4.1 cm 
B) +20 cm 
C) -9.9 cm 
D) -20 cm 
E) +9.9 cm 
A) -4.1 cm 
B) +20 cm 
C) -9.9 cm 
D) -20 cm 
E) +9.9 cm

Question 11

An object is placed in front of a convex mirror at a distance larger than twice the magnitude of the focal length of the mirror.The image will appear

Accepted Answer

A) in front of the mirror. 
B) inverted and reduced. 
C) inverted and enlarged. 
D) upright and reduced. 
E) upright and enlarged. 
A) in front of the mirror. 
B) inverted and reduced. 
C) inverted and enlarged. 
D) upright and reduced. 
E) upright and enlarged.

Question 12

An object is placed 15 cm to the left of a convex lens of focal length 20 cm.Where is the image of this object located?

Accepted Answer

A) 60 cm to the right of the lens 
B) 60 cm to the left of the lens 
C) 8.6 cm to the right of the lens 
D) 8.6 cm to the left of the lens 
E) 30 cm to the left of the lens 
A) 60 cm to the right of the lens 
B) 60 cm to the left of the lens 
C) 8.6 cm to the right of the lens 
D) 8.6 cm to the left of the lens 
E) 30 cm to the left of the lens

Question 13

The length of a telescope is 2.20 m and the focal length of the eyepiece is 1.9 cm.What is the focal length of the objective lens?

Accepted Answer

A) 41 cm 
B) 45 cm 
C) 111 cm 
D) 218 cm 
E) 16 cm 
A) 41 cm 
B) 45 cm 
C) 111 cm 
D) 218 cm 
E) 16 cm

Question 14

A cell phone that is 8.90 cm tall is placed in front of a convex mirror.The image of the phone is 7.80 cm tall and is located 14.8 cm from a mirror.What is the mirror's focal length?

Accepted Answer

A) -120 cm 
B) -105 cm 
C) +16.9 cm 
D) -13.0 cm 
E) +120 cm 
A) -120 cm 
B) -105 cm 
C) +16.9 cm 
D) -13.0 cm 
E) +120 cm

Question 15

A statue that is 2.3 cm tall is placed 15 cm in front of a convex mirror.The magnitude of the radius of curvature of the mirror is 18 cm.
(a)Is the image real or virtual?
(b)How far is the image from the mirror?
(c)Is the image upright or inverted?
(d)How tall is the image?

Accepted Answer

(a)virtual

Question 16

What type of lens is used to make a magnifying glass?

Accepted Answer

A) convex 
B) concave 
C) Either type would work equally well. 
A) convex 
B) concave 
C) Either type would work equally well.

Question 17

If a single lens forms a virtual image of an object,then

Accepted Answer

A) the lens must be a concave lens. 
B) the lens must be a convex lens. 
C) the lens could be either a concave or a convex lens. 
D) the image must be inverted. 
E) the object must be between the lens and its focal point. 
A) the lens must be a concave lens. 
B) the lens must be a convex lens. 
C) the lens could be either a concave or a convex lens. 
D) the image must be inverted. 
E) the object must be between the lens and its focal point.

Question 18

Tan's face is 20 cm in front of a concave shaving mirror.If he observes his image to be twice as big and upright,what is the focal length of the mirror?

Accepted Answer

A) 10 cm 
B) -40 cm 
C) -50 cm 
D) 40 cm 
E) 50 cm 
A) 10 cm 
B) -40 cm 
C) -50 cm 
D) 40 cm 
E) 50 cm

Question 19

You may have seen ambulances on the street with the letters of the word AMBULANCE written on the front of them,in such a way as to appear correctly when viewed in your car's rear-view mirror.(See the figure.)How do the letters appear when you look directly at the ambulance (not through the mirror)? a)   
b)   
c)  
d)   
e)

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 20

A 4.0-cm tall object is placed 60 cm in front of a convex lens of focal length of magnitude 30 cm.What are the nature and location of the image?

Accepted Answer

A) The image is real, 2.5 cm tall, 30 cm on the same side as object. 
B) The image is virtual, 2.5 cm tall, 30 cm on the other side of the lens. 
C) The image is virtual, 2.0 cm tall, 15 cm on the other side of the lens. 
D) The image is virtual, 4.0 cm tall, 60 cm on the same side as object. 
E) The image is real, 4.0 cm tall, 60 cm on the other side of the lens. 
A) The image is real, 2.5 cm tall, 30 cm on the same side as object. 
B) The image is virtual, 2.5 cm tall, 30 cm on the other side of the lens. 
C) The image is virtual, 2.0 cm tall, 15 cm on the other side of the lens. 
D) The image is virtual, 4.0 cm tall, 60 cm on the same side as object. 
E) The image is real, 4.0 cm tall, 60 cm on the other side of the lens.

Exam 23: Mirrors and Lenses

When a flower petal is 4.0 cm in front of a convex lens,the inverted image is half the height of the petal.What is the focal length of this lens?

Mary builds a simple refracting telescope using two lenses of focal length 80 cm and 5.0 cm.The respective diameters are 60 mm and 10 mm.How many degrees wide does the moon appear through the telescope if it appears only 1/2 degree wide with the "naked eye"?

A slide projector is set up with its lens 6.0 m from the screen.The projected image on the screen is 1.5 m square for a slide (the object)that is 2.5 cm square. (a)How far is the slide from the lens? (b)What is the focal length of the projector lens?

A nearsighted person has a far point that is 4.2 m from his eyes.What power contact lenses must he wear to allow him to focus on distant mountains?

An object is 50 cm from a concave mirror of radius of curvature of magnitude 60 cm.How far is the image from the mirror?

A person's face is 30 cm in front of a concave spherical shaving mirror.If the image is an erect image that is 1.5 times as large as the object,what is the focal length mirror?

Alice is farsighted and cannot see objects clearly that are closer to her eye than 80.0 cm.What is the refractive power of the contact lenses that will enable her to comfortably see objects at a distance of 25.0 cm from her eyes?

A toy is 14 cm in front of a convex spherical mirror.If the image of the toy is 5.8 cm behind the mirror,what is the focal length of the mirror?

An object is placed in front of a convex mirror at a distance larger than twice the magnitude of the focal length of the mirror.The image will appear

An object is placed 15 cm to the left of a convex lens of focal length 20 cm.Where is the image of this object located?

The length of a telescope is 2.20 m and the focal length of the eyepiece is 1.9 cm.What is the focal length of the objective lens?

A cell phone that is 8.90 cm tall is placed in front of a convex mirror.The image of the phone is 7.80 cm tall and is located 14.8 cm from a mirror.What is the mirror's focal length?

A statue that is 2.3 cm tall is placed 15 cm in front of a convex mirror.The magnitude of the radius of curvature of the mirror is 18 cm. (a)Is the image real or virtual? (b)How far is the image from the mirror? (c)Is the image upright or inverted? (d)How tall is the image?

What type of lens is used to make a magnifying glass?

If a single lens forms a virtual image of an object,then

Tan's face is 20 cm in front of a concave shaving mirror.If he observes his image to be twice as big and upright,what is the focal length of the mirror?

A 4.0-cm tall object is placed 60 cm in front of a convex lens of focal length of magnitude 30 cm.What are the nature and location of the image?

Introduction

Kinematics: Motion in One Dimension

Newtonian Mechanics

Applying Newtons Laws

Circular Motion

Impulse and Linear Momentum

Work and Energy

Extended Bodies at Rest

Rotational Motion

Gases

Static Fluids

Fluids in Motion

First Law of Thermodynamics

Second Law of Thermodynamics

Electric Charge force and Energy

The Electric Field

Dc Circuits

Magnetism

Electromagnetic Induction

Vibrational Motion

Mechanical Waves

Reflection and Refraction

Wave Optics

Electromagnetic Waves

Special Relativity

Quantum Optics

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