PSC 1121 - Chapter 7 - LIGHT Exam Questions with Correct Answers Latest Update
2026/2027
A scientist might model light as electromagnetic waves to understand how an incandescent
lightbulb works. She might model light as rays to Blank__________. - Answers - design the optics
of a microscope
- understand the reflection from a glass window
An object that produces light is said to be ____________. - Answers Blank 1: luminous
Filament lightbulbs, the wires in a toaster, and a fire are all examples of ___________ light
sources, which produce light over a wide range of wavelengths. - Answers Blank 1:
incandescent
In the production of light by an incandescent source, internal heat moves particles that make up
the glowing object. The moving nuclei and electrons Blank______. - Answers disturb the electric
and magnetic fields in the material, creating electromagnetic radiation
Reason:
Accelerating charged particles create electromagnetic waves. The hotter the object, the more
acceleration occurs, and the more light is produced.
Visible light is only a small part of the entire ___________ spectrum, which is shown in the figure.
- Answers Blank 1: electromagnetic
Match the model of light to what it can be used for. - Answers - Electromagnetic wave model ---
Explain the generation of light at a source.
- Representing light as a ray ---- Predict the angle of a reflection off a mirror.
- Particle model ---- Explain light as individual packets of energy.
Objects that are luminous ___________. - Answers produce light
Rank the different types of electromagnetic radiation by their frequency, with the lowest
frequency on the top. - Answers 1. Radio Waves
2. Infrared Light
3. Visible Light
4. Ultraviolet Light
5. X Rays
,6. Gamma Rays
Select all the choices that are incandescent light sources. - Answers - The Sun
- A candle
An animal or plant that is bioluminous can produce visible ____________. - Answers Blank 1: light
The light produced by incandescent light sources is generated by _____________. - Answers
accelerating electric charges
True or false: All objects with heat produce blackbody radiation. - Answers True
Reason:
For objects at "room temperature," this radiation is mainly in infrared wavelengths, so they do
not appear to be glowing unless you use special cameras.
The figure shows the Blank______. - Answers electromagnetic spectrum
Select all that occur as the temperature of an object emitting blackbody radiation increases. -
Answers - More light is produced.
- The peak of the emission shifts to bluer (shorter) wavelengths.
A scientist might model light as electromagnetic waves to understand how an incandescent
lightbulb works. She might model light as rays to Blank______. - Answers - understand the
reflection from a glass window
- design the optics of a microscope
The temperature needed for an object to glow red is Blank__________ the temperature needed
for an object to glow white. - Answers lower than
Match the type of electromagnetic radiation with its frequency and common use(s). - Answers -
Microwaves ---- Lowest frequency; cellular phones, broadcast television, cooking
- Infrared light ---- Second lowest frequency; remote controls, night-vision equipment
- X rays ---- Second highest frequency; dental and medical imaging
- Gamma rays ---- Highest frequency; medical treatments
Plants and animals that emit visible light are said to be Blank______. - Answers bioluminous
Sunlight is primarily made up of Blank______ - Answers infrared radiation
, Incandescent light sources produce _____________ radiation, which is shown in the graph. -
Answers Blank 1: blackbody
If you were designing a microscope or telescope, the _______________ _____________model would
be helpful for tracing light's path through the device. - Answers Blank 1: light
Blank 2: ray
The graph shows the blackbody emission from three flames that are the same size. Rank the
flames by temperature, from hottest (top) to coolest (bottom). Note: Radiation intensity is on
the y-axis. - Answers Z
Y
X
Match the terms related to light to their definitions. - Answers - Reflection----Happens when light
bounces off a smooth surface
- Opaque ----- An object that reflects and/or absorbs all the light that hits it
- Diffuse reflection ---- The result of light hitting a rough surface
- Transparent ----- An object that transmits light
A hot object (such as an electric burner) starts to glow red when the temperature reaches
Blank______. An incandescent lightbulb (tungsten filament) glows yellow-white at a temperature
of about Blank______. (Select two.) - Answers - 2,200°C (4,000°F)
- 700°C (1,300° F)
Identify the objects shown based on the behavior of light rays hitting them. One object is not
shown. - Answers - Object One ---- A silver mirror
- Object Two ---- A white rug
- Choice ----- A diamond
Sunlight has a broad-spectrum centered near the Blank______frequency. - Answers yellow-green
Select all that are key features of the light ray model. - Answers - Light can be absorbed.
- Light changes direction as it enters and exits materials with different properties.
- Light travels in straight lines.
At what time of day would you expect the most glare off a lake next to the highway? - Answers
mid-sunrise
2026/2027
A scientist might model light as electromagnetic waves to understand how an incandescent
lightbulb works. She might model light as rays to Blank__________. - Answers - design the optics
of a microscope
- understand the reflection from a glass window
An object that produces light is said to be ____________. - Answers Blank 1: luminous
Filament lightbulbs, the wires in a toaster, and a fire are all examples of ___________ light
sources, which produce light over a wide range of wavelengths. - Answers Blank 1:
incandescent
In the production of light by an incandescent source, internal heat moves particles that make up
the glowing object. The moving nuclei and electrons Blank______. - Answers disturb the electric
and magnetic fields in the material, creating electromagnetic radiation
Reason:
Accelerating charged particles create electromagnetic waves. The hotter the object, the more
acceleration occurs, and the more light is produced.
Visible light is only a small part of the entire ___________ spectrum, which is shown in the figure.
- Answers Blank 1: electromagnetic
Match the model of light to what it can be used for. - Answers - Electromagnetic wave model ---
Explain the generation of light at a source.
- Representing light as a ray ---- Predict the angle of a reflection off a mirror.
- Particle model ---- Explain light as individual packets of energy.
Objects that are luminous ___________. - Answers produce light
Rank the different types of electromagnetic radiation by their frequency, with the lowest
frequency on the top. - Answers 1. Radio Waves
2. Infrared Light
3. Visible Light
4. Ultraviolet Light
5. X Rays
,6. Gamma Rays
Select all the choices that are incandescent light sources. - Answers - The Sun
- A candle
An animal or plant that is bioluminous can produce visible ____________. - Answers Blank 1: light
The light produced by incandescent light sources is generated by _____________. - Answers
accelerating electric charges
True or false: All objects with heat produce blackbody radiation. - Answers True
Reason:
For objects at "room temperature," this radiation is mainly in infrared wavelengths, so they do
not appear to be glowing unless you use special cameras.
The figure shows the Blank______. - Answers electromagnetic spectrum
Select all that occur as the temperature of an object emitting blackbody radiation increases. -
Answers - More light is produced.
- The peak of the emission shifts to bluer (shorter) wavelengths.
A scientist might model light as electromagnetic waves to understand how an incandescent
lightbulb works. She might model light as rays to Blank______. - Answers - understand the
reflection from a glass window
- design the optics of a microscope
The temperature needed for an object to glow red is Blank__________ the temperature needed
for an object to glow white. - Answers lower than
Match the type of electromagnetic radiation with its frequency and common use(s). - Answers -
Microwaves ---- Lowest frequency; cellular phones, broadcast television, cooking
- Infrared light ---- Second lowest frequency; remote controls, night-vision equipment
- X rays ---- Second highest frequency; dental and medical imaging
- Gamma rays ---- Highest frequency; medical treatments
Plants and animals that emit visible light are said to be Blank______. - Answers bioluminous
Sunlight is primarily made up of Blank______ - Answers infrared radiation
, Incandescent light sources produce _____________ radiation, which is shown in the graph. -
Answers Blank 1: blackbody
If you were designing a microscope or telescope, the _______________ _____________model would
be helpful for tracing light's path through the device. - Answers Blank 1: light
Blank 2: ray
The graph shows the blackbody emission from three flames that are the same size. Rank the
flames by temperature, from hottest (top) to coolest (bottom). Note: Radiation intensity is on
the y-axis. - Answers Z
Y
X
Match the terms related to light to their definitions. - Answers - Reflection----Happens when light
bounces off a smooth surface
- Opaque ----- An object that reflects and/or absorbs all the light that hits it
- Diffuse reflection ---- The result of light hitting a rough surface
- Transparent ----- An object that transmits light
A hot object (such as an electric burner) starts to glow red when the temperature reaches
Blank______. An incandescent lightbulb (tungsten filament) glows yellow-white at a temperature
of about Blank______. (Select two.) - Answers - 2,200°C (4,000°F)
- 700°C (1,300° F)
Identify the objects shown based on the behavior of light rays hitting them. One object is not
shown. - Answers - Object One ---- A silver mirror
- Object Two ---- A white rug
- Choice ----- A diamond
Sunlight has a broad-spectrum centered near the Blank______frequency. - Answers yellow-green
Select all that are key features of the light ray model. - Answers - Light can be absorbed.
- Light changes direction as it enters and exits materials with different properties.
- Light travels in straight lines.
At what time of day would you expect the most glare off a lake next to the highway? - Answers
mid-sunrise
