Waves

Question 1

Electromagnetic Spectrum sentence

Answer 1

Rich Men In Vegas Use Xpensive Glasses DWIF

Question 2

Electromagnetic spectrum

Answer 2

Radio
Micro
Infrared
Visible
Ultraviolet
X-ray
Gamma

Question 3

What does DWIF stand for

Answer 3

Decreasing Wavelength Increasing Frequency

Question 4

Uses for Radio Waves

Answer 4

Radio and TV communication

Question 5

Uses for Micro Waves

Answer 5

Satellite Communication and Cooking

Question 6

Uses for Infrared Waves

Answer 6

Heaters and Night vision equipment

Question 7

Uses for Visible Waves

Answer 7

Human sight

Question 8

Uses for Ultraviolet Waves

Answer 8

Fluorescent lamps

Question 9

Uses for X-ray Waves

Answer 9

Medical imaging and security

Question 10

Uses for Gamma Waves

Answer 10

Sterelising food or medical equipment

Question 11

Speed of electromagnetic waves is

Answer 11

the same in a vacuum and roughly the same in air

Question 12

Critical angle is when

Answer 12

the refracted beam runs along the line between the two mediums

Question 13

Total internal reflection is when the

Answer 13

angle of incidence is sufficiently large such that the beam does not refract but reflects back into the object

Question 14

Total internal reflection occurs when

Answer 14

angle of incidence > critical angle

Question 15

sin (critical angle) =

Answer 15

1/optical density or 1/n

Question 16

Optical fibres are

Answer 16

1. thin rods of glass
2. which use total internal reflection
3. to transfer information using light

Question 17

Uses of Optical fibres

Answer 17

1. medicine - e.g. endoscopes
2. communications - e.g. data transfer

Question 18

Hazards of Microwaves

Answer 18

Internal heating of body tissue

Question 19

Hazards of Infrared waves

Answer 19

Skinburn

Question 20

Hazards of Ultraviolet waves

Answer 20

Skin cancer and blindness

Question 21

Hazards of X-rays

Answer 21

Mutations leading to cancer

Question 22

Hazards of Gamma waves

Answer 22

Mutations leading to cancer

Question 23

To estimate the speed of sound in air

Answer 23

1. Make a noise at a known large distance form a solid wall
2. Record the time taken for the echo to be hear
3. Use speed=distance/time, where distance is twice the length as the sound had to go there and back

Question 24

Waves transfer

Answer 24

energy and information without transferring matter

Question 25

Transverse waves have

Answer 25

1. Peaks and troughs 2. Vibrations perpendicular to the direction of travel

Question 26

Example of Transverse waves

Answer 26

Light

Question 27

Longitudinal Waves have

Answer 27

1. Compressions (particles pushed together) then Rarefactions (particles moved apart) 2. Vibrations parallel to the direction of travel

Question 28

Example of Longitudinal waves

Answer 28

Sound

Question 29

Quiet, low pitch longitudinal waves have

Answer 29

a small amplitude and a long wavelength

Question 30

Loud, high pitch longitudinal waves have

Answer 30

a big amplitude and a short wavelength

Question 31

Amplitude

Answer 31

Distance from equilibrium point to maximum or minimum point

Question 32

Wavefront

Answer 32

Line through points that are at the same point in their wave cycle

Question 33

Frequency (f)

Answer 33

Number of waves per second

Question 34

Frequency is measured in

Answer 34

Hertz (Hz)

Question 35

Wavelength (lamda)

Answer 35

distance between corresponding points on adjacent waves

Question 36

Time period (T)

Answer 36

time for a wave to pass a fixed point

Question 37

Frequency eqauls

Answer 37

1/Time period

Question 38

Speed of a wave equals

Answer 38

Frequency x Wavelength

Question 39

The Doppler effect explanation

Answer 39

1. If the wave source is moving relative to an observer 2. The observed frequency and wavelength will change 3. When moving towards, the waves will be bunched together leading to a shorter wavelength, greater frequency and higher pitch 4. When moving away, the waves will be more spaced apart, leading to longer wavelength, lower frequency and lower pitch

Question 40

Can all waves be reflected?

Answer 40

Yes

Question 41

With reflection, angle of incidence equals

Answer 41

the angle of reflection

Question 42

When a wave is reflected these remain unchanged

Answer 42

Frequency, Wavelength and Speed

Question 43

Can all waves be refracted?

Answer 43

Yes

Question 44

Refraction occurs when a wave enters...

Answer 44

...a medium of a different density

Question 45

The process of refraction when entering a medium of a lower density

Answer 45

1. Speed increases 2. Wave bends away from the normal 3. Incidence angle is less than the refracted angle

Question 46

The process of refraction when entering a medium of a higher density

Answer 46

1. Speed decreases 2. Wave bends towards the normal 3. Incidence angle is greater than the refracted angle

Question 47

With Refraction, this remains unchanged

Answer 47

Frequency

Question 48

With Refraction, these two things change

Answer 48

Wavelength and Speed