waves

State 2 uses of radio waves.

Radio, television, radar, wireless computer networks, bluetooth

What word is used for a space containing no particles?

Vacuum

What word is used for the number of waves passing a point each second?

Frequency

What word is used for the change of direction when light hits a boundary between media?

Refraction

How do radio waves transfer the signal to a receiver?

Radio waves are absorbed creating an alternating current with the same frequency as the radio wave

When light travels from a less optically dense medium to a more optically dense medium what happens to the speed of the wave?

Decreases

What is an oscillation?

A vibration

State 1 use of xrays.

Imaging of bones

State the visible spectrum in order from highest frequency to lowest frequency (first letters will do).

VIBGYOR (i.e. Violet, Infrared, Blue, Green, Yellow, Orange, Red)

What is an echo?

A reflected sound wave

Which quantity doesn't change during refraction?

Frequency

What does perpendicular mean?

At 90 degrees

What are the risks of xrays and gamma waves?

Mutation of genes, cancer

When a wave hits a boundary at 0ᵒ to the normal (head on), why does the change of speed not lead to refraction?

Every point on the wavefront hits the boundary and changes speed at the same time

State the visible spectrum in order from longest wavelength to shortest wavelength (first letters will do).

ROYGBIV (i.e. Red, Orange, Yellow, Green, Blue, Indigo, Violet)

State the unit of wave speed.

Metres per second OR m/s

Why are electromagnetic waves useful for communications.

They travel very fast and through a vacuum/air

Describe one piece of evidence that a sound wave transfers energy without transferring matter.

The air around a drum does not move away, creating a vacuum

What word is used for the distance from a point on one wave to the equivalent point on the adjacent wave?

Wavelength

How are frequency and wavelength related when wave speed is kept constant?

Inversely proportional

Define a transverse wave.

The oscillations are perpendicular to the direction of energy transfer

What is a wavefront?

A peak, when seen from above

When light travels from a more optically dense medium to a less optically dense medium what happens to the angle between the ray and the normal?

Increases

When a wave hits a boundary at an angle, why does the change of speed lead to refraction?

The edge of the wavefront which hits the boundary first changes speed first

When a light ray travels from a more optically dense medium to a less optically dense medium does it bend towards or away from the normal?

Away from

How should light rays be drawn on diagrams?

Straight lines with arrows

What property of a light wave determines it brightness/intensity?

Amplitude

What are the risks of ultraviolet radiation?

Skin aging prematurely, increased risk of skin cancer, eye damage

What kind of materials do not transmit any light?

Opaque

What type of surface is the best emitter and absorber of infrared radiation?

Matt, black

What is the angle between a wavefront and a ray?

90ᵒ

Which type of wave has oscillations perpendicular to the direction of energy transfer?

Transverse

What does parallel mean?

In the same direction

In what case does a wave travelling between media not refract?

When the angle of incidence is 0ᵒ

State the speed of light in a vacuum.

300,000,000 m/s

State 2 uses of visible light.

Optical fibres, photography, lasers

When light travels from a more optically dense medium to a less optically dense medium what happens to the wavelength of the wave?

Increases

State the unit of frequency.

Hertz OR Hz

When light travels from a more optically dense medium to a less optically dense medium what happens to the speed of the wave?

Increases

Why can sound not travel through a vacuum.

Sound waves need particles to travel. Vacuums contain no particles.

Do water waves travel faster in deeper or shallower water?

Deeper

Are electromagnetic waves transverse or longitudinal?

Transverse

What is the word for: Some of a wave's energy is lost inside the material.

Absorption

What word is used for the region in a longitudinal wave where the particles are further apart?

Rarefaction

State the electromagnetic waves in order from highest frequency to lowest frequency (first letters will do).

GXUVIMR (i.e. Gamma, Xray, Ultraviolet, Visible, Infrared, Microwave, Radio)

Which objects emit infrared radiation?

All objects

When light travels from a less optically dense medium to a more optically dense medium what happens to the wavelength of the wave?

Decreases

Which objects absorb infrared radiation?

All objects

What kind of materials transmit most light with little reflection or absorption?

Transparent

Which type of wave are sound waves travelling through air?

Longitudinal

What are the 3 things which happen when a wave meets a boundary between media?

Transmission, reflection and absorption

What word is used for the material which a wave travels through?

Medium

State the wave equation in words.

Wave speed = Frequency x Wavelength

State an example of a medium less optically dense than glass.

Air

Which electromagnetic wave can be detected by our eyes?

Visible light

Which type of EM wave can be emitted from changes in the nucleus of atoms?

Gamma

What word is used for the maximum displacement of a point on a wave away from its undisturbed position?

Amplitude

What is the full rainbow of colour called?

Spectrum

State the unit of time period.

Seconds OR s

What word is used for a reflected sound wave?

Echo

What is the lowest point on a transverse wave called?

Trough

State a typical value of speed for sound in air.

330 m/s

Define frequency.

The number of waves passing a point each second

State 2 uses of ultraviolet.

Energy efficient lamps, sun tanning (dangerous), banknote security

What is the dotted line drawn perpendicular to a boundary called?

Normal

Complete the sentence: ….............. objects emit more infrared radiation than ….............. objects.

Hotter, colder

How many millsieverts in a sievert?

1000

Which type of wave has areas of compression and rarefaction?

Longitudinal

How is wavelength best measured in a ripple tank?

Measure across 10 waves and divide by 10

State 2 uses of infrared.

Electrical heaters, cooking food, infrared cameras, remote controls, optical fibres

When white light passes through a prism it splits into all the colours of the rainbow. What is this called?

Dispersion

What is the angle between a normal and a boundary?

90ᵒ

How do we see objects?

Light reflects off the objects into our eyes

State the wave equation in symbols.

v = fλ

How are radio waves produced in a transmitter?

Alternating current with the same frequency as the radio waves

Which type of wave are the ripples on a water surface?

Transverse

Why is ionising radiation used in medicine despite the risks?

Benefit is greater than risk

How are wave speed and wavelength related when frequency is kept constant?

Directly proportional

State 2 examples of transverse waves.

Light, water ripples

What type of surface is the worst emitter and absorber of infrared radiation?

Shiny, white

State the electromagnetic waves in order from longest wavelength to shortest wavelength (first letters will do).

RMIVUXG (i.e. Radio, Microwave, Infrared, Visible, Ultraviolet, Xray, Gamma)

What word is used for the region in a longitudinal wave where the particles are closer together?

Compression

What is the speed of all electromagnetic waves in a vacuum or air?

300,000,000 m/s or 3 x 10⁸ m/s

What is the distance between 2 consecutive wavefronts?

Wavelength

What word is used for when something gives out electromagnetic radiation?

emit

Why are microwaves used to communicate with distant satellites?

They pass straight through the atmosphere

State 1 example of a longitudinal wave.

Sound

When does refraction occur?

When a wave moves from one medium to another

What is the highest point on a transverse wave called?

peak

When a light ray travels from a less optically dense medium to a more optically dense medium does it bend towards or away from the normal?

Towards

Which type of wave has oscillations parallel to the direction of energy transfer?

Longitudinal

When a wave transfers energy from place to place what are the individual particles in the wave doing?

Oscillating

State an example of a medium more optically dense than air.

Water OR glass

What property of a light wave determines its colour?

Frequency OR wavelength

Briefly describe an experiment to measure the speed of sound in air.

Measure time for echo. Speed = distance/time.

How do xrays form images of bones?

They are absorbed by bone but pass through soft tissue

State 2 uses of microwaves.

Satellite communications, heating food

When light travels from a less optically dense medium to a more optically dense medium what happens to the angle between the ray and the normal?

Decreases

State 2 uses of gamma rays.

Treating cancer, medical tracing, sterilising food and medical equipment

Why does dispersion happen?

Different colours (wavelengths) of light refract different amounts