PHY 131 EXAM 11 | QUESTIONS AND
ANSWERS | 2026 UPDATE | WITH
COMPLETE SOLUTIONS
In Huygens's construction, all points on a wave front: a. act as point sources for the production of secondary
spherical waves. b. act as particles. c. demonstrate the dual nature of light. d. must be sources of plane waves. -
ANSWER>a
One phenomenon that demonstrates the particle nature of light is: a. the photoelectric effect. b. diffraction effects.
c. interference effects. d. the prediction by Maxwell's electromagnetic theory. - ANSWER>a
The lowest possible value for the index of refraction is: a. 0. b. 1. c. (square root of 2)/2. d. 1/(square root of 3) -
ANSWER>b
A ray of light passes from one material into a material with a higher index of refraction. Which quantity remains
unchanged? a. The light's speed b. The light's wavelength c. The light ray's angle with the normal d. The photon
energy - ANSWER>d
,The wave-particle duality of light means that, in the same experiment: a. light will act both like a wave and like a
particle. b. light will act either like a wave or like a particle. c. light will not act like either a wave or a particle. d.
light always exists as two waves or as two particles. - ANSWER>b
When light from air hits a smooth piece of glass (n = 1.5) with the ray perpendicular to the glass surface, which of
the following will occur? a. reflection and transmission with θ2 = 0° b. refraction with θ2 = 41.8° c. interference d.
All of the above will occur - ANSWER>a
Who formulated the theory explaining the photoelectric effect? a. Hertz b. Maxwell c. Newton d. Einstein -
ANSWER>d
A light ray incident on the interface between air and glass can undergo total internal reflection: a. only in the glass.
b. only in the air. c. in either the glass or the air. d. in the air only if the index of refraction of the glass is greater
than the square root of 2 - ANSWER>a
A slab of plastic rests on a slab of glass. A ray of light in the plastic crosses the interface between the plastic and the
glass with the result that the ray bends toward the normal. What must be true about the indices of refraction in
these materials? a. nplastic > nglass b. nplastic < nglass c. nplastic = nglass d. More information is needed to decide
the answer - ANSWER>b
, What is the cause of refraction of a wave traveling from one medium to another? a. There is a frequency change
due to the change in the medium b. There is a speed change due to the change in the medium. c. There is a change
in wave amplitude due to the change in the medium. d. None of the above are associated with refraction. -
ANSWER>b
When the reflection of an object is seen in a concave mirror the image will a. always be real. b. always be virtual. c.
may be either real or virtual. d. will always be enlarged. - ANSWER>c
An object is placed at a distance of 41.4 cm from a thin lens along the axis. If a real image forms at a distance of
36.1 cm from the lens, on the opposite side from the object, what is the focal length of the lens? a. 19.3 cm b. 38.8
cm c. 10.6 cm d. 282 cm e. 6.21 cm - ANSWER>a
The magnification for a flat mirror: a. is a function of the image distance. b. is a function of the object distance. c. is
a function of the object and image distances. d. is 1 - ANSWER>d
When the midpoint of the face of the Sun appears to be on the horizon, where is the actual midpoint from the
point of view of the observer? a. above the horizon at sunrise and below the horizon at sunset b. on the horizon c.
below the horizon d. above the horizon - ANSWER>c
ANSWERS | 2026 UPDATE | WITH
COMPLETE SOLUTIONS
In Huygens's construction, all points on a wave front: a. act as point sources for the production of secondary
spherical waves. b. act as particles. c. demonstrate the dual nature of light. d. must be sources of plane waves. -
ANSWER>a
One phenomenon that demonstrates the particle nature of light is: a. the photoelectric effect. b. diffraction effects.
c. interference effects. d. the prediction by Maxwell's electromagnetic theory. - ANSWER>a
The lowest possible value for the index of refraction is: a. 0. b. 1. c. (square root of 2)/2. d. 1/(square root of 3) -
ANSWER>b
A ray of light passes from one material into a material with a higher index of refraction. Which quantity remains
unchanged? a. The light's speed b. The light's wavelength c. The light ray's angle with the normal d. The photon
energy - ANSWER>d
,The wave-particle duality of light means that, in the same experiment: a. light will act both like a wave and like a
particle. b. light will act either like a wave or like a particle. c. light will not act like either a wave or a particle. d.
light always exists as two waves or as two particles. - ANSWER>b
When light from air hits a smooth piece of glass (n = 1.5) with the ray perpendicular to the glass surface, which of
the following will occur? a. reflection and transmission with θ2 = 0° b. refraction with θ2 = 41.8° c. interference d.
All of the above will occur - ANSWER>a
Who formulated the theory explaining the photoelectric effect? a. Hertz b. Maxwell c. Newton d. Einstein -
ANSWER>d
A light ray incident on the interface between air and glass can undergo total internal reflection: a. only in the glass.
b. only in the air. c. in either the glass or the air. d. in the air only if the index of refraction of the glass is greater
than the square root of 2 - ANSWER>a
A slab of plastic rests on a slab of glass. A ray of light in the plastic crosses the interface between the plastic and the
glass with the result that the ray bends toward the normal. What must be true about the indices of refraction in
these materials? a. nplastic > nglass b. nplastic < nglass c. nplastic = nglass d. More information is needed to decide
the answer - ANSWER>b
, What is the cause of refraction of a wave traveling from one medium to another? a. There is a frequency change
due to the change in the medium b. There is a speed change due to the change in the medium. c. There is a change
in wave amplitude due to the change in the medium. d. None of the above are associated with refraction. -
ANSWER>b
When the reflection of an object is seen in a concave mirror the image will a. always be real. b. always be virtual. c.
may be either real or virtual. d. will always be enlarged. - ANSWER>c
An object is placed at a distance of 41.4 cm from a thin lens along the axis. If a real image forms at a distance of
36.1 cm from the lens, on the opposite side from the object, what is the focal length of the lens? a. 19.3 cm b. 38.8
cm c. 10.6 cm d. 282 cm e. 6.21 cm - ANSWER>a
The magnification for a flat mirror: a. is a function of the image distance. b. is a function of the object distance. c. is
a function of the object and image distances. d. is 1 - ANSWER>d
When the midpoint of the face of the Sun appears to be on the horizon, where is the actual midpoint from the
point of view of the observer? a. above the horizon at sunrise and below the horizon at sunset b. on the horizon c.
below the horizon d. above the horizon - ANSWER>c
