Light

Light

What is light?
How does light travel?

Light is a type of electromagnetic

radiation that can be detected by the

eye.

It travels as a transverse wave in little packets of energy called photons.

Unlike sound waves, light waves do not

need a medium to pass through, they

can travel through a vacuum.

Light from the Sun reaches Earth

through the vacuum of space.

Multiple Choice

A form of energy that travels in straight lines

• sound

• light

• kinetic

• atoms

Multiple Choice

What is NOT one of the 3 main types of mediums?

• Solid

• Liquid

• plastic

• Gas

Multiple Choice

Light is a kind of.....

• reflection

• energy

• heat

• matter

Multiple Choice

Which of these describes how light travels through an empty space?

• It travels straight but may change direction to avoid objects.

• It changes direction often even if there are no objects. 

• It comes to a stop after it travels a certain distance. 

• It travels in a straight line without stopping. 

Multiple Choice

A tiny bundle of energy by which light travels

• Photographs

• Photos

• Photons

• Friends

Multiple Choice

A region that contains few or no particles

• Vacuum

• Velocity

• Velcro

• Volcano

Multiple Choice

A substance through which light travels.

• Wavelength

• Opaque

• Frequency

• Medium

What is the speed of light?

How does the speed of light compare to the speed of sound?

The speed of light in air is 300 000 000 m/s (300
million m/s), which is nearly a million times
faster than the speed of sound, which is 340
m/s.

The very large difference between the speed of
light and the speed of sound explains why you:

See lightning before you hear it.

See a distant firework explode before you hear
it.

See a distant hockey stick hit a ball before you
hear it.

Multiple Choice

Light is a kind of.....

• reflection

• energy

• heat

• matter

Multiple Choice

What is the most accurate measured value of the speed of light?

• 3 x 10⁸ m/s

• 186,000 miles/s

• 299,792,458 m/s

• 300,000 km/s

Multiple Choice

How long can it take light from stars in another galaxy to travel to earth?

• 60 years

• Millions of years ago

• It depends on how far away the star is.

• None of the above

Multiple Choice

Why doesn't sound travel through outer space?

• Sound only travels through outer space.

• Sound can travel through outer space.

• Sound can only travel through matter.

• None of the above

Multiple Choice

Which is faster, the speed of light or the speed of sound?

• They are both very fast.

• The speed of light.

• The speed of sound.

• None of the above

Multiple Choice

Why haven't people traveled faster than the speed of light?

• Chuck Yeager has traveled faster than the speed of light.

• We do not have sufficient technology to travel thousands of light years away.

• None of the above

Multiple Select

How fast does light travel

• 300 000 000 m/s

• 3x10⁸ m/s

• 3 m/s

• 300 000 000 km/s

Multiple Choice

True/False: Nothing can go faster than the speed of light

• True

• False

Multiple Choice

True or false: The light that is emitted by the Sun reaches earth instantly

• False

• True

This is a band of radiations of continuous wavelengths.

Radio waves have the lowest frequencies and longest wavelengths, while gamma waves have the highest frequencies and shortest wavelengths.

All of these waves travel at the same speed in free space, which is the speed of light or about 300,000,000 m/s (metres per second).

The Electromagnetic Spectrum

This is a band of radiations of continuous wavelengths.

Radio waves have the lowest frequencies and longest wavelengths, while gamma waves have the highest frequencies and shortest wavelengths.

All of these waves travel at the same speed in free space, which is the speed of light or about 300,000,000 m/s (metres per second).

The Electromagnetic Spectrum

Hazards of electromagnetic radiation

Over-exposure to certain types of electromagnetic radiation can be harmful.

The higher the frequency of the radiation, the more energy it carries and the more damage it is likely to cause to the body:

• microwaves can cause internal heating of body tissues;

• infrared radiation is felt as heat and causes skin to burn;

• visible light from a laser which is very intense can damage the retina at the back of the eye;

• ultraviolet can damage skin cells and lead to skin cancer and damage the eyes, it can cause skin to age prematurely;

• X-rays damage cells inside the body. They cause dangerous ionisation and when this happens with molecules in living cells, the genetic material of a cell, the DNA is damaged. This can lead to cancer. This is why doctors and dentists stand behind protective screens when taking lots of X-rays;

• gamma rays also damage cells inside the body causing dangerous ionisation in living cells which damages DNA. This can lead to cell death and cancer.

Hazards of electromagnetic radiation

Multiple Choice

What electromagnetic wave has the shortest wavelengths and the highest frequencies?

• Gamma Rays

• Ultraviolet Rays

• Radio Waves

• X Rays

Multiple Choice

What happens to wavelength as the frequency of a wave increases?

• increase

• stays the same

• decreases

• becomes faster

Multiple Choice

What electromagnetic wave has the longest wavelengths and lowest frequencies?

• Microwaves

• Ultraviolet Rays

• Infrared Waves

• Radio Waves

Multiple Choice

The human eye is only capable of seeing which electromagnetic wave?

• Infrared Light

• Ultraviolet Light

• Visible Light

• All of the above

Multiple Choice

What electromagnetic wave do humans emit as heat energy?

• infrared light

• ultraviolet light

• visible light

• microwaves

Multiple Choice

Which of the following is correct in order from lowest to highest energy?

• X Rays, Visible Light, Microwave

• Ultraviolet, Visible Light, Gamma-Rays

• Microwave, Visible Light, Gamma Rays

Multiple Choice

Which type of electromagnetic wave has the longest wavelength?

• visible light

• radio waves

• ultraviolet waves

• gamma rays

Multiple Choice

The color blue has more energy than the color red.

• True

• False

Multiple Choice

Radio waves, visible light, and x rays are examples of electromagnetic waves that always differ from each other in

• amplitude

• intensity

• temperature

• wavelength

Multiple Choice

What wave helps the skin make Vitamin D and helps the body absorb calcium?

• Infrared

• Visible light

• Microwave

• Ultraviolet Rays

Multiple Choice

This type of electromagnetic wave has different colors of light that all have different wavelengths.

• Gamma Rays

• Microwaves

• Infrared

• Visible Light

Multiple Choice

This type of electromagnetic wave has the most energy and therefore can be very dangerous.

• Microwaves

• Radio Waves

• X Rays

• Gamma Rays

Multiple Choice

This type of electromagnetic wave can be used to see inside luggage at an airport or in hospitals to see your bones.

• Gamma Rays

• Visible Light

• X Rays

• Infrared Rays

Multiple Choice

Which of the following has the electromagnetic waves going from least amount of energy to most amount of energy?

• Radio Waves, Infrared, X Rays

• Gamma, Infrared, Microwaves

• Microwaves, Radio, X Rays

• Visible Light, Infrared, Microwaves

Multiple Choice

In the electromagnetic spectrum, which of the following is true of waves with long wavelengths?

• They have high frequencies

• They have low frequencies

• They have moderate frequencies

• They have inconsistent frequencies

Multiple Choice

Sunscreen bottles often include the phrase: “Protects against UVA and UVB waves.” This refers to ultraviolet radiation coming from the sun. Which of the following is true of ultraviolet radiation?

• Ultraviolet radiation has shorter wavelengths than x-rays, therefore it is more dangerous than xrays.

• Ultraviolet radiation has longer wavelengths than infrared light, therefore it is more dangerous than infrared light.

• Ultraviolet radiation has shorter wavelengths than visible light, therefore it is more dangerous than visible light.

• Ultraviolet radiation has longer wavelengths than gamma radiation, therefore it is more dangerous than gamma radiation.

Multiple Choice

The full range of energy in sunlight can be described as

• ATP

• Visible Light

• Electromagnetic Radiation

• Ultraviolet Light

Multiple Choice

What part of the electromagnetic spectrum can be seen by humans?

• Visible Light

• Microwaves

• Ultraviolet Waves

• Infrared Waves

Multiple Choice

Which feature best distinguishes one form of electromagnetic energy from another?

• Color

• Wavelength

• Surface Temperature

• Distance Traveled

Multiple Choice

Which of the following is NOT a type of radiation present in radiation from the sun?

• Infrared

• Ultraviolet

• Visible

• Radio

Multiple Choice

Which has a higher frequency?

• Wave N

• Wave O

• Same frequency

• There is no frequency

Multiple Choice

The distance between E and H is called

• Crest

• Wavelength

• Amplitude

• Frequency

Multiple Choice

Our eyes detect light that lies only within a small region of the electromagnetic spectrum. This region is called visible light. Which of these statements describes the visible spectrum of light as seen by the human eye?

• The lowest frequency appears red, and the highest frequency appears violet.

• The lowest frequency appears green, and the highest frequency appears red.

• The lowest frequency appears blue, and the highest frequency appears orange.

• The lowest frequency appears yellow, and the highest frequency appears green.

Multiple Choice

The electromagnetic spectrum is made up of bands of waves with different _____

• Speeds

• Frequencies

• Reflections

• Mediums

Multiple Choice

The diagram below shows the electromagnetic spectrum. Which letters represent radio and gamma waves?

• A F

• F C

• A G

• C G

Multiple Choice

All of the waves listed below are a part of the electromagnetic spectrum except

• X Rays

• Sound Waves

• Gamma Rays

• Light Waves

Multiple Choice

How does the hazard level of electromagnetic waves change as the frequency of the waves increases?

• Energy and wavelength increase; it becomes more hazardous.

• Energy and wavelength decrease; becomes less hazardous.

• Energy decreases, wavelength increases; it becomes less hazardous.

• Energy increases, wavelength decreases; it becomes more hazardous.

Multiple Choice

Electromagnetic waves come in many different wavelengths. Shorter wavelengths carry more energy and penetrate further through materials. People wear sunblock to prevent UV waves from damaging their skin cells. Which kind of wave has enough energy to pass through skin and damage cells on the inside of the body?

• Visible Light

• Infrared

• Gamma Rays

• Radio Waves

Multiple Choice

Meg is barbequing hamburgers on the grill. She notices that the coals are ready for cooking because she feels the warmth of the coals and sees that they are glowing red. What types of electromagnetic waves is she detecting?

• infrared waves and visible light waves

• gamma rays and infrared waves

• visible light and ultraviolet waves

• ultraviolet waves and gamma rays

Multiple Choice

Electromagnetic radiation is energy that travels in waves. Two types of electromagnetic waves are microwaves and gamma rays. Gamma rays have a shorter wavelength than microwaves. Which of these statements is true?

• Gamma rays travel faster than microwaves in a vacuum.

• Gamma rays have more energy than microwaves do.

• Gamma rays have a lower frequency than microwaves do.

• Gamma rays, but not microwaves, can travel through a vacuum.

Multiple Choice

The different types of electromagnetic radiation are usually organized on the electromagnetic spectrum from radio waves to gamma waves. Why are they arranged in this order?

• They are arranged in order of decreasing energy

• They are arranged in order of decreasing frequency

• They are arranged in order of how useful the light is

• They are arranged in order of decreasing wavelength

What is the law of reflection?

How many types of reflections can be produced when light is reflected?

Law of reflection: Angle of reflection is always equal to the angle of incidence.

When light hits a smooth surface, a specular reflection is produced.

When light hits a rough or uneven surface, a diffuse reflection is produced

Multiple Choice

In the diagram, which letter represents the angle of incidence?

• A

• B

• C

• D

Multiple Choice

Which diagram represents specular reflection?

• A

• B

Multiple Choice

Law of reflection state that - The angle of incidence is .................. to the angle of reflection.

• equal

• double

• half

Multiple Choice

........... – the angle between the normal and the reflected ray.

• Angle of incidence

• Angle of reflection

• Angle of coincidence

• Angle of direction

Multiple Choice

What is reflection?

• Reflection is the bouncing  of light off the surface that it strikes on.

• Reflection is the absorbing of light off the surface that it strikes on.

• Reflection is the bending of light off the surface that it strikes on.

• Reflection is the scattering of light off the surface that it strikes on.

Multiple Choice

........... – the angle between the normal and the incident ray.

• Angle of incidence

• Angle of reflection

• Angle of coincidence

• Angle of direction

Multiple Choice

........... – the angle between the normal and the incident ray.

• Angle of incidence

• Angle of reflection

• Angle of coincidence

• Angle of direction

Multiple Choice

How does light travel

• It curves around corners

• Really slow

• In a straight line

• In circles

Multiple Choice

The ray of light that strikes a reflecting surface is called ________.

• incident ray

• reflected ray

• normal ray

• none of the above

Multiple Choice

The imaginary line perpendicular to a reflecting surface is called _____.

• crooked line

• parallel line

• angular line

• normal line

Multiple Choice

If the angle of incidence is 45 degree, what is the angle between the incident ray and reflecting surface

• 45

• 90

• 180

• none of the above

What are shadows?

How are shadows formed?

Shadows are formed because light travels in a straight line.

When light hits an opaque object a shadow is formed because the object prevents the light from reaching the ground.

Multiple Choice

Which light source causes shadows in the outdoor environment? 

• The Sun

• The Lightbulb

• The House

• The School

Multiple Choice

When is a shadow formed?

• When the light is turned off

• When the path of light is blocked by an object

• When an object falls to the floor

• When the light it turned on

Multiple Choice

Transparent is?

• A material that allows light to pass through

• The colors of the rainbow

• Light made by man

Multiple Choice

When an object blocks the path of light, what is formed?

• A problem

• A fog

• A reflection

• A shadow

Multiple Choice

Where will the tree's shadow be?

• A

• B

• C

Multiple Choice

Opaque is?

• A material that does not allow light to pass through

• The colors of the rainbow

• Light made by man

Multiple Choice

Where will the tree's shadow be?

• A

• B

• C

Multiple Choice

Which position of the sun will make the longest shadow?

• A

• B

• C

Multiple Choice

True or False:

A shadow is the light area created by an object that stops light.

• True

• False

Fill in the Blanks

Multiple Choice

Which is NOT a source of light?

• firefly

• ball

• sun

• falshlight

Multiple Choice

Which light source is artificial?

• sun

• firefly

• lightning

• flashlight

Multiple Choice

Which source of light is natural?

• firworks

• lightbulb

• lightning

• headlights

Multiple Choice

What causes a shadow?

• turning the lights off in a room

• standing still with your back to the sun

• the sun being blocked out by an object

• standing in a dark room