Question 1

Without his contact lenses, Mr.Chong can focus from 0.80 m to infinity.What refractive power of the lenses does he require for normal reading (0.25 m from the eyes)?

Accepted Answer

A) 1.25 diopters 
B) 2.75 diopters 
C) 4.00 diopters 
D) 5.25 diopters 
E) -5.25 diopters

Question 2

26-2
Light is incident at the Brewster angle on a plastic plate in air.The angle of refraction is 35.0°.
-What is the index of refraction of the plastic plate?

Accepted Answer

A) 1.58 
B) 1.36 
C) 1.43 
D) 1.61 
E) 1.74

Question 3

A converging lens is used to focus light from a small bulb onto a book.The lens has a focal length of 10.0 cm and is located 40.0 cm from the book.Determine the distance from the lens to the light bulb.

Accepted Answer

A) 8.6 cm 
B) 13 cm 
C) 20 cm 
D) 30 cm 
E) 50 cm

Question 4

When an object is placed 20 cm from a diverging lens, a reduced image is formed.Which one of the following statements is necessarily true?

Accepted Answer

A) The image is inverted. 
B) The image could be real. 
C) The image distance must be greater than 20 cm. 
D) The focal length of the lens may be less than 20 cm. 
E) The refractive power of the lens must be greater than 0.05 diopters.

Question 5

The figure is a scaled diagram of a an object and a converging lens.The focal length of the lens is 5.0 units.An object is placed 3.0 units from the lens as shown. 
-Approximately, what is the image distance?

Accepted Answer

A) -2.0 units 
B) -4.0 units 
C) +6.0 units 
D) -7.5 units 
E) +9.0 units

Question 6

Light with a wavelength of 589 nm in a vacuum strikes the surface of an unknown liquid at an angle of 31.2° with respect to the normal to the surface.If the light travels at a speed of 1.97 × 108 m/s through the liquid, what is the angle of refraction?

Accepted Answer

A) 19.9° 
B) 26.1° 
C) 34.2° 
D) 39.3° 
E) 51.9°

Question 7

A beam of light that consists of a mixture of red, green and violet light strikes a prism (surrounded by air) as shown.Indices of refraction for this prism for the various colors are indicated in the table.An observer is located to the right of the prism as shown.  
-Which physical phenomenon is illustrated by the fact that the prism has different refractive indices for different colors?

Accepted Answer

A) Doppler effect 
B) dispersion 
C) diffraction 
D) total internal reflection 
E) interference

Question 8

An object is placed at the focal point of a thin diverging lens of focal length f.What is the image distance?

Accepted Answer

A) f 
B) 2f 
C) 1/f 
D) f/2 
E) at an infinite distance

Question 9

In her biology class, Chris examines an insect wing under a compound microscope that has an objective lens with a focal length of 0.70 cm, an eyepiece with a focal length of 3.0 cm, and a lens separation distance of 16.00 cm.Chris has a near point distance of 22.5 cm.What is the approximate angular magnification of the microscope as Chris views the insect wing?

Accepted Answer

A) -75 
B) -110 
C) -140 
D) -190 
E) -250

Question 10

Which one of the following statements best explains why chromatic aberration occurs in lenses, but not in mirrors?

Accepted Answer

A) The shape of the mirror prevents chromatic aberration. 
B) The thickness of a lens varies from top to bottom. 
C) The frequency of light changes when it passes through glass. 
D) The angle of incidence varies over the surface of a lens for incident parallel rays of light. 
E) Different colors of light are refracted by different amounts as the light passes through a lens.

Question 11

Kaitlynne is using a magnifying glass (f = 0.098 m) while trying to solder a computer circuit board.The image is 0.21 m from the lens.What is the distance between the glass and the circuit board?

Accepted Answer

A) 0.052 m 
B) 0.062 m 
C) 0.067 m 
D) 0.093 m 
E) 0.16 m

Question 12

A camera with a focal length of 0.0500 m (a 50-mm lens) is focused for an object at infinity.To focus the camera on a subject which is 4.00 m away, how should the lens be moved?

Accepted Answer

A) 1.0 cm closer to the film 
B) 0.06 cm closer to the film 
C) 4.94 cm closer to the film 
D) 0.06 cm farther from the film 
E) 4.94 cm farther from the film

Question 13

26-13
A fish swims 4.0 m below the surface of a still lake as shown in the figure.When an archer attempts to shoot the fish, the arrow enters the water at point P that is a horizontal distance 1.2 m from the fish. 
-Which one of the following phrases most accurately describes the image of the fish as seen by the archer?

Accepted Answer

A) real and inverted 
B) virtual and inverted 
C) real and reversed right to left 
D) virtual with its orientation unaltered 
E) real with its orientation unaltered

Question 14

A certain type of glass is used in making flat-panel computer monitors.For light with a wavelength in air of 656.3 nm, the refractive index of the glass is nA = 1.5160.For light with a wavelength in air of 435.8 nm, nB = 1.5290.Determine the difference, $\lambda$A  - $\lambda$B , in their wavelengths inside the glass.

Accepted Answer

A) 147.9 nm 
B) 156.0 nm 
C) 220.5 nm 
D) 268.4 nm 
E) 293.1 nm

Question 15

A ray of blue light travels through air and is refracted as it enters a glass prism shown in the figure.An unknown liquid is in contact with the right side of the prism.The light then follows the path shown.Which one of the following statements concerning this situation is true?

Accepted Answer

A) The frequency of the light changes inside the prism. 
B) The index of refraction of the glass is smaller than that of air. 
C) The index of refraction of the unknown liquid is the same as that of the glass. 
D) The speed of light is larger in the liquid than in the glass. 
E) The refractive index of the liquid is the same as that of air.

Question 16

A ray of light propagates in water (n = 1.333) and strikes a sheet of crown glass (n = 1.523).If the angle of refraction in the glass is 35.2°, determine the angle of incidence.

Accepted Answer

A) 30.3° 
B) 32.8° 
C) 35.2° 
D) 41.2° 
E) 45.0°

Question 17

White light enters a glass prism, but the color components of the light are observed to emerge from the prism.Which one of the following statements best explains this observation?

Accepted Answer

A) The separation of white light into its color components is due to the increase in the speed of light within the glass. 
B) Some of the color components of the white light are absorbed by the glass and only the remaining components are observed. 
C) The index of refraction of the glass depends on the wavelength, so the color components are refracted at different angles. 
D) Only some of the color components are refracted by the glass; and these are the ones that are observed. 
E) White light is separated into its color components by total internal reflection within the prism.

Question 18

The figure shows a point source of unpolarized light at A inside a uniform transparent crystal.The ray AO in the crystal strikes the plane surface SS' making an angle of 30° with the normal.This angle is the critical angle for transmission into air. 
-Which one of the following statements is true concerning this situation?

Accepted Answer

A) When the angle of incidence is equal to the Brewster angle, the angle of refraction is 13°. 
B) When the angle of incidence is equal to the Brewster angle, the angle of refraction is 63°. 
C) When the angle of incidence is equal to the Brewster angle, the angle of refraction is 42°. 
D) Since the Brewster angle is less than the critical angle, there is no refraction when the angle of incidence is equal to $\theta$B. 
E) Since the Brewster angle is greater than the critical angle, there is no refraction when the angle of incidence is equal to $\theta$ B.

Question 19

The speed of light in material A is 1.4 times as large as it is in material B.What is the ratio of the refractive indices, nA/nB, of these materials?

Accepted Answer

A) 1.4 
B) 1.2 
C) 1.0 
D) 0.80 
E) 0.71

Question 20

A beam of light that consists of a mixture of red, green and violet light strikes a prism (surrounded by air) as shown.Indices of refraction for this prism for the various colors are indicated in the table.An observer is located to the right of the prism as shown.  
-Which physical phenomenon is illustrated by the fact that the emerging rays are spread into the component colors of the beam?

Accepted Answer

A) Doppler effect 
B) dispersion 
C) diffraction 
D) total internal reflection 
E) interference

Exam 26: The Refraction of Light: Lenses and Optical Instruments

Without his contact lenses, Mr.Chong can focus from 0.80 m to infinity.What refractive power of the lenses does he require for normal reading (0.25 m from the eyes) ?

26-2 Light is incident at the Brewster angle on a plastic plate in air.The angle of refraction is 35.0°. -What is the index of refraction of the plastic plate?

A converging lens is used to focus light from a small bulb onto a book.The lens has a focal length of 10.0 cm and is located 40.0 cm from the book.Determine the distance from the lens to the light bulb.

When an object is placed 20 cm from a diverging lens, a reduced image is formed.Which one of the following statements is necessarily true?

The figure is a scaled diagram of a an object and a converging lens.The focal length of the lens is 5.0 units.An object is placed 3.0 units from the lens as shown. -Approximately, what is the image distance?

Light with a wavelength of 589 nm in a vacuum strikes the surface of an unknown liquid at an angle of 31.2° with respect to the normal to the surface.If the light travels at a speed of 1.97 × 10⁸ m/s through the liquid, what is the angle of refraction?

An object is placed at the focal point of a thin diverging lens of focal length f.What is the image distance?

Which one of the following statements best explains why chromatic aberration occurs in lenses, but not in mirrors?

Kaitlynne is using a magnifying glass (f = 0.098 m) while trying to solder a computer circuit board.The image is 0.21 m from the lens.What is the distance between the glass and the circuit board?

A camera with a focal length of 0.0500 m (a 50-mm lens) is focused for an object at infinity.To focus the camera on a subject which is 4.00 m away, how should the lens be moved?

A ray of light propagates in water (n = 1.333) and strikes a sheet of crown glass (n = 1.523) .If the angle of refraction in the glass is 35.2°, determine the angle of incidence.

White light enters a glass prism, but the color components of the light are observed to emerge from the prism.Which one of the following statements best explains this observation?

The speed of light in material A is 1.4 times as large as it is in material B.What is the ratio of the refractive indices, n_A/n_B, of these materials?