Question 1

The speed of light in a certain medium is 2.2 × 108 m/s. What is the index of refraction of this medium?

Accepted Answer

A)  1.0 
B)  1.2 
C)  1.4 
D)  1.6 
E)  1.8 
A)  1.0 
B)  1.2 
C)  1.4 
D)  1.6 
E)  1.8

Question 2

The reflection of light from a rough surface is called specular reflection.

Accepted Answer

A) True 
 B)False

Question 3

A concave mirror always produces a real image of an object placed in front of it.

Accepted Answer

A) True 
 B)False

Question 4

An object is placed at F in front of a concave mirror with a focal length of 10 cm. What is the position of its image in relation to the mirror and what are its characteristics?

Accepted Answer

A)  = 10 cm, real, smaller than object 
B)  = 10 cm, virtual, smaller than object 
C)  = 20 cm, real, bigger than object 
D)  = 20 cm, virtual, bigger than object 
E)  = ∞, real, much bigger than the object 
A)  = 10 cm, real, smaller than object 
B)  = 10 cm, virtual, smaller than object 
C)  = 20 cm, real, bigger than object 
D)  = 20 cm, virtual, bigger than object 
E)  = ∞, real, much bigger than the object

Question 5

When a beam of light in air is incident at an angle of incidence θi < 90° on a piece of glass, the angle of refraction is larger than the angle of incidence.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following is a correct statement?

Accepted Answer

A)  A concave mirror always produces a real image. 
B)  A convex mirror always produces a virtual image. 
C)  A concave mirror always produces a virtual image. 
D)  A convex mirror always produces a real image. 
E)  All of the previous statements can be correct. 
A)  A concave mirror always produces a real image. 
B)  A convex mirror always produces a virtual image. 
C)  A concave mirror always produces a virtual image. 
D)  A convex mirror always produces a real image. 
E)  All of the previous statements can be correct.

Question 7

An image is 4.0 cm behind a concave mirror with focal length 5.0 cm. Where is the object?

Accepted Answer

A)  2.2 cm in front of the mirror 
B)  2.2 cm behind the mirror 
C)  9.0 cm in front of the mirror 
D)  1.0 cm behind the mirror 
E)  20 cm behind the mirror 
A)  2.2 cm in front of the mirror 
B)  2.2 cm behind the mirror 
C)  9.0 cm in front of the mirror 
D)  1.0 cm behind the mirror 
E)  20 cm behind the mirror

Question 8

At a quiet pond with crystal clear water, you decide to fish with bow and arrow. When you aim at the fish you see, you must aim

Accepted Answer

A)  closer to the surface then you perceive the fish to be. 
B)  directly at the fish. 
C)  deeper then you perceive the fish to be. 
D)  It depends on how large the fish is. 
E)  It depends on how deep the pond is. 
A)  closer to the surface then you perceive the fish to be. 
B)  directly at the fish. 
C)  deeper then you perceive the fish to be. 
D)  It depends on how large the fish is. 
E)  It depends on how deep the pond is.

Question 9

An object is placed 9.5 cm from a lens of focal length 24 cm.
(a) Where is the image formed?
(b) What is the magnification?

Accepted Answer

(a)16 cm from the le

Question 10

An object is placed 10 cm from a convex lens of focal length 20 cm. What is the magnification?

Accepted Answer

A)  0.50 
B)  1.0 
C)  1.5 
D)  2.0 
E)  2.5 
A)  0.50 
B)  1.0 
C)  1.5 
D)  2.0 
E)  2.5

Question 11

David stands 2.5 meters in front of a plane mirror.
(a) How far from David is David's image in the mirror?
(b) If David moves away from the mirror at 1.5 m/s, how fast are David and his image moving apart from each other?
(c) If David is 180. cm tall, how tall is his image in the mirror?

Accepted Answer

(a)5.0 cm

Question 12

A mirror is rotated at an angle of 10° from its original position. How much is the rotation of the angle of reflection?

Accepted Answer

A)  10° 
B)  5° 
C)  15° 
D)  20° 
E)  40° 
A)  10° 
B)  5° 
C)  15° 
D)  20° 
E)  40°

Question 13

A parallel light beam containing two wavelengths, 480. nm and 700. nm, strikes a plain piece of glass at an angle of incidence of 60°. The index of refraction of the glass is 1.4830 at 480. nm and 1.4760 at 700. nm. Determine the angle between the two beams in the glass.

Accepted Answer

The answer of A parallel light beam containing two wavelengths,...

Question 14

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

Accepted Answer

A)  10 cm 
B)  20 cm 
C)  30 cm 
D)  40 cm 
E)  50 cm 
A)  10 cm 
B)  20 cm 
C)  30 cm 
D)  40 cm 
E)  50 cm

Question 15

The image distance,   , is positive for images in front of a mirror.

Accepted Answer

A) True 
 B)False

Question 16

The end of a cylindrical plastic rod is polished and cut perpendicular to the axis of the cylinder. Determine the minimum index of refraction so that a light ray entering the end of the rod will always be totally internally reflected within the rod, i.e., it will never escape the rod until it comes to the other end. Assume a critical angle of 45°.

Accepted Answer

The answer of The end of a cylindrical plastic rod...

Question 17

To burn a hole in a piece of paper using light from the Sun, which mirror would work the best?

Accepted Answer

A)  Plane 
B)  Convex 
C)  Concave 
D)  All of the given answers would work equally as well. 
E)  None of the given answers would burn a hole. 
A)  Plane 
B)  Convex 
C)  Concave 
D)  All of the given answers would work equally as well. 
E)  None of the given answers would burn a hole.

Question 18

According to Huygens' principle, each point on a wave can be considered as the source of a new wave that propagates from that point onward.

Accepted Answer

A) True 
 B)False

Question 19

The index of refraction of a certain medium is 1.5. What is the speed of light in that medium?

Accepted Answer

A)  1.0 × 108 m/s 
B)  2.0 × 108 m/s 
C)  3.0 × 108 m/s 
D)  4.0 × 108 m/s 
E)  5.0 × 108 m/s 
A)  1.0 × 108 m/s 
B)  2.0 × 108 m/s 
C)  3.0 × 108 m/s 
D)  4.0 × 108 m/s 
E)  5.0 × 108 m/s

Question 20

A ray of light consisting of blue light (wavelength 480 nm) and red light (wavelength 670 nm) is incident on a thick piece of glass at 80°. What is the angular separation between the refracted red and refracted blue beams while they are in the glass? (The respective indices of refraction for the blue light and the red light are 1.4636 and 1.4561.)

Accepted Answer

A)  0.277° 
B)  0.455° 
C)  0.330° 
D)  0.155° 
E)  0.341° 
A)  0.277° 
B)  0.455° 
C)  0.330° 
D)  0.155° 
E)  0.341°

Exam 26: Geometrical Optics

The speed of light in a certain medium is 2.2 × 108 m/s. What is the index of refraction of this medium?

The reflection of light from a rough surface is called specular reflection.

A concave mirror always produces a real image of an object placed in front of it.

An object is placed at F in front of a concave mirror with a focal length of 10 cm. What is the position of its image in relation to the mirror and what are its characteristics?

When a beam of light in air is incident at an angle of incidence θi < 90° on a piece of glass, the angle of refraction is larger than the angle of incidence.

Which of the following is a correct statement?

An image is 4.0 cm behind a concave mirror with focal length 5.0 cm. Where is the object?

At a quiet pond with crystal clear water, you decide to fish with bow and arrow. When you aim at the fish you see, you must aim

An object is placed 9.5 cm from a lens of focal length 24 cm. (a) Where is the image formed? (b) What is the magnification?

An object is placed 10 cm from a convex lens of focal length 20 cm. What is the magnification?

David stands 2.5 meters in front of a plane mirror. (a) How far from David is David's image in the mirror? (b) If David moves away from the mirror at 1.5 m/s, how fast are David and his image moving apart from each other? (c) If David is 180. cm tall, how tall is his image in the mirror?

A mirror is rotated at an angle of 10° from its original position. How much is the rotation of the angle of reflection?

A parallel light beam containing two wavelengths, 480. nm and 700. nm, strikes a plain piece of glass at an angle of incidence of 60°. The index of refraction of the glass is 1.4830 at 480. nm and 1.4760 at 700. nm. Determine the angle between the two beams in the glass.

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

The image distance, , is positive for images in front of a mirror.

To burn a hole in a piece of paper using light from the Sun, which mirror would work the best?

According to Huygens' principle, each point on a wave can be considered as the source of a new wave that propagates from that point onward.

The index of refraction of a certain medium is 1.5. What is the speed of light in that medium?

Introduction to Physics

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The speed of light in a certain medium is 2.2 × 10⁸ m/s. What is the index of refraction of this medium?

When a beam of light in air is incident at an angle of incidence θ_i < 90° on a piece of glass, the angle of refraction is larger than the angle of incidence.