Waves, Electricity and Magnetism

Question 1

Define Waves

Answer 1

An oscillation that carries energy and information from one place to another

Question 2

What are different types of waves?

Answer 2

1. Travelling

2. Stationary

Question 3

What can travelling waves be?

Answer 3

1. Longitudinal

2. Transverse

Question 4

What are the different shapes of wave?

Answer 4

1. Sine wave
2. Square wave
3. Triangle and sawtooth wave

Question 5

What are longitudinal wave?

Answer 5

Oscillation of the particle go parallel to the direction of propagation of the wave

Question 6

What are examples of transverse waves?

Answer 6

Ripples on surface of water

Question 7

What are examples of longitudinal waves?

Answer 7

sound waves travelling in the air

Question 8

What are transverse waves?

Answer 8

Oscillations are perpendicular to the direction of wave propagation

Question 9

Transverse waves

Answer 9

The oscillations are up and down but the direction of energy transfer is sideways

Question 10

Longitudinal wave: how does sound waves travel?

Answer 10

Particles in air

move from side to side

Question 11

What do all longitudinal wave require?

Answer 11

A medium to travel in e.g. air, liquid and solid

Question 12

What are examples of transverse waves from a medical perpesctives?

Answer 12

1. X-ray - lateral x-rays of the skull
2. NIRS
3. Radiowaves

Question 13

What are examples of properties of waves?

Answer 13

1. Amplitude
2. Wavelength
3. Frequency
4. Period

Question 14

Define amplitude

Answer 14

The amplitude of a wave is the maximum displacement of a point on a wave away from its undisturbed position

Question 15

What is amplitude?

Answer 15

The furthest point the wave vibrates from this undisturbed position

Question 16

What is wavelength of wave?

Answer 16

Distance from a point on one wave to the equivalent point on the adjacent wave

Question 17

Wavelength

Answer 17

Take a point on one wave e.g. the top then measure the distance to the same point on the next wave then that is the wavelength

Question 18

what is the symbol for wavelength ?

Answer 18

Greek letter lambda

Question 19

what is the frequency?

Answer 19

The number of waves passing a point each second

Question 20

What is unit of frequency?

Answer 20

Hertz (Hz)

1 Hz = 1 wave per second

Question 21

What is the period?

Answer 21

Time (in seconds) for one wave to pass a point

Question 22

What is equation of period?

Answer 22

1/Frequency T=1/f

Question 23

What are the examples of wave behaviour?

Answer 23

1. Interference and superposition
2. Reflection
3. Refraction
4. Diffraction

Question 24

What is interference?

Answer 24

Combined effect of the disturbance caused by each individual wave at the same place and at same time

Question 25

What is the principle of superposition?

Answer 25

When two or more waves travel through the same medium simultaneously, the resultant displacement at any point is the vector sum of the displacement due to the individual waves

Question 26

What is standing waves?

Answer 26

When two waves of the same frequency travelling in opposite directions add together observed in microwave ovens

Question 27

What is speed of light?

Answer 27

Constant in a vacuum | 3x10ms-1

Question 28

What is wavelength of electromagnetic rod

Answer 28

speed of wave/frequency

Question 29

What are 2 ways of reflection?

Answer 29

1. Specular | 2. Diffuse

Question 30

What can the surface of a material do?

Answer 30

Transmit, absorb or reflect a wave

Question 31

What is specular reflection?

Answer 31

Angle of incidence = Angle of reflection e.g. light on mirror

Question 32

What is diffuse reflection?

Answer 32

Reflection of wave from a surface in which the incident wave is reflected at multiple angles

Question 33

What is refraction?

Answer 33

The change in direction of propagation of a wave as it passes through different materials

Question 34

What is diffraction?

Answer 34

A range of phenomenen observed when waves interact with slits, edges and other obstacles

Question 35

What is electromagnetic waves?

Answer 35

Transverse waces | Transfer energy from the source of the waves to an absorber

Question 36

What is a small part of the electromagnetic spectrum?

Answer 36

Visible light

Question 37

What is example of low frequency and long wavelength?

Answer 37

Radiowaves Microwaves Infrared

Question 38

What are examples of high frequency and short wavelength?

Answer 38

Visible light Ultraviolet X-rays Gamma rays

Question 39

Where does the wavelength decrease?

Answer 39

Radiowaves to Gamma rays

Question 40

What are the sources of magnetic field?

Answer 40

``` Current in wire Loop of wire Solenoid Bar magnet The earth ```

Question 41

What does the size and direction of force depend on?

Answer 41

Distribution of field lines

Question 42

What is strength of magnetic field measured in?

Answer 42

Telsa

Question 43

region of low flux density

Answer 43

weak field