# 14. P12 P13 Waves and EM Waves (Trilogy) Flashcards Preview

## SHHS - Science - Physics GCSE 2018on > 14. P12 P13 Waves and EM Waves (Trilogy) > Flashcards

Flashcards in 14. P12 P13 Waves and EM Waves (Trilogy) Deck (50)
1
Q

What is the law of reflection?

A

Angle of incidence(i) = Angle of reflection(r)

2
Q

What is a transverse wave?

A

The particle oscillations are perpendicular to the direction of the energy.

3
Q

Give examples of transverse waves.

A

light, water, radio, microwave, infrared, UV, X-rays, Gamma

4
Q

What is a longitudinal wave?

A

The particle oscillations are parallel to the direction of the energy.

5
Q

Give an example of a longitudinal wave.

A

Sound

6
Q

What is a wave?

A

A wave transfers energy and information from one place to another.

7
Q

Define Wavelength

A

The Wavelength is the length of one complete wave. (the distance between two corresponding points on a wave)

8
Q

Units of wavelength?

A

Metres (although can be measured in mm, cm or km)

9
Q

Define Amplitude

A

The amplitude is the maximum disturbance caused by a wave from its rest position. (centre line of wave up to the peak or down to the trough)

10
Q

Define frequency

A

The frequency is the number of waves passing a point every second.

11
Q

Units of frequency?

A

Hertz (or Hz - must be capital H)

12
Q

Define period (T)

A

The period is the time it takes for one complete wave to pass a point

13
Q

Units of time period (T) of a wave?

A

seconds, s

14
Q

Equation to calculate wave speed?

A

wavespeed = frequency x wavelength (v = f x ?) (? - lambda = wavelength)

15
Q

Equation to calculate time period of a wave from the frequency?

A

T = 1 / f

16
Q

In a longitudinal wave, the name given to areas where the particles are close together?

A

Compression

17
Q

In a longitudinal wave, the name given to areas where the particles are spread out?

A

Rarefaction

18
Q

What is refraction of waves?

A

The change in the direction of travel when a wave crosses a boundary between one medium to another due to the wave changing speed.

19
Q

Water waves refract when what causes the speed of the wave to change?

A

Depth of the water

20
Q

Light waves refract when what causes the speed of the wave to change?

A

Moves from one material to another of a different optical density.

21
Q

The line on a ray diagram that all angles are measured from during reflection or refraction?

A

normal

22
Q

How do you draw a normal line at the point the light strikes the mirror?

A

Normal line is drawn perpendicular to the surface at the point the ray strikes the surface (using a dashed line)

23
Q

What is the speed of sound waves in air?

A

330m/s although it does vary with temperature.

24
Q

How does a sound change when the amplitude decreases?

A

Quieter

25
Q

How does a sound change when the Wavelength increases?

A

Lower pitch

26
Q

How does a sound change when the frequency increases?

A

Higher Pitch

27
Q

Describe what is meant by a mechanical wave.

A

A wave that requires a medium in which to travel i.e. water or a spring etc

28
Q

Describe what is meant by an electromagnetic wave.

A

Transverse waves that transfer energy by setting up electric and magnetic fields. Can travel through a vacuum.

29
Q

What is meant by the crest or peak of a wave?

A

The highest part of a transverse wave

30
Q

What is meant by the trough of a wave?

A

The lowest part of a transverse wave

31
Q

List the Electromagnetic waves in order from long to short wavelength

A

Radio, Microwave, Infrared, Visible, UV, X-ray and Gamma

32
Q

List the Electromagnetic waves in order from high to low frequency

A

Gamma, X-ray, UV, Visible, IR, Microwave, Radio

33
Q

State how a radiowave can be produced?

A

Oscillation in electrical circuits (vibration of charged particle such as electron)

34
Q

A

35
Q

State two uses of microwaves?

A

Heat food, mobile phones, Satelite tv, GPS

36
Q

State two uses of infrared?

A

heater, toaster, oven, treatment of muscle injuries, remote controls, infrared cameras

37
Q

State two uses of UV light?

A

Check for forged bank notes, sunbeds, investigating crime scenes, energy efficient lightbulbs.

38
Q

State two uses of X-rays?

A

airport security, check for broken bones

39
Q

State two uses of Gamma radiation?

A

Radiotherapy, sterilising surgical equipment, medical tracers, industrial tracers

40
Q

What are the two similarities of all electromagnetic waves?

A

All transverse, travel at the same speed in vacuum or air, transfer energy

41
Q

State the colours which make up visible light?

A

Red,Orange, Yellow, Green, Blue, Indigo and Violet.

42
Q

State a danger of UV light?

A

Ultraviolet waves can cause skin to age prematurely and increase the risk of skin cancer.

43
Q

State which types of EM waves are ionising radiation?

A

UV, X-ray and Gamma

44
Q

State what the effect on human tissue when they absorb Radio, Microwave, IR or visible?

A

Heating

45
Q

State what effect ionising radiation can have on human cells?

A

Can cause the mutation of genes and cancer.

46
Q

What two things do the effects of ionising radiation have on human body tissue depend on?

A

1) type of radiation and 2) the size of the dose.

47
Q

Radiation dose is measured in Sieverts, what is it a measure of?

A

It is the measure of the risk of harm resulting from an exposure of the body to the radiation.

48
Q

How many millisieverts are present in 5 sieverts of radiation dose?

A

5000millisieverts = 5 sieverts

49
Q

Which type of EM radiation can be used by fibre optic cables?

A

IR and visible light

50
Q

How are gamma rays generated?

A

Gamma rays are generated from changes within the nucleus of atoms.