Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

iGCSE Physics > Waves > Flashcards

Waves Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Complete this sentence. Waves transfer___and___ without tranferring___.

A

Energy. Information. Matter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define frequency and give its units.

A

-The number of waves passing through a point per second.
-Hz (hertz)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define wavelength.

A

The distance between two adjacent peaks on a wave.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define amplitude

A

-Maximum displacement of the wave from its equilibrium position.
-The distance between the centre of the wave and the peak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is meant by the period of the wave?

A

The length of time it takes for one full wave to pass through a point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How can you calculate the wavespeed?

A

v = f λ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

State the equation linking frequency and periods of a wave

A

Frequency (Hz) = 1/Period (s)

f=1/T
1/fxT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a longitudinal wave?

A

-Vibration are parallel to the direction of energy transfer
-Examples include sound waves and earthquakes (seismic waves).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a transverse wave?

A

-A wave with oscillations that are perpendicular to the direction of energy transfer.
-Examples include electromagnetic waves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain the doppler effect.

A

When a wave source is moving towards an observer, observed frequency increases and observed wavelength decreases; when a wave source is moving away from the observer, observed frequency decreases and observed wavelength decreases since v = f λ and speed is in constant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

At what speed does an electromagnetic wave travel in a vacuum?

A

3x10⁸ m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What type of waves are electromagnetic waves?

A

Transverse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the 4 common properties of electromagnetic waves?

A

-Transverse
-Transfer energy or info
-All travel at the speed of light in vacuum
-They can be reflected, refracted or diffracted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Order the electromagnetic spectrum from the highest frequency to the lowest frequency.

A

Gamma rays, x-rays, ultraviolet, visible light, infrared, microwaves and radio waves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the uses of radio waves?

A

-Communication through radio
-Used for satellite trasmissions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are microwaves used for?

A

-Cooking in microwaves ovens
-Communications
-Satellites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are infrared radiations used for?

A

-Cooking
-Thermal imaging
-Television remote controls

18
Q

What is ultraviolent light used for?

A

-Security marking
-Fluorescent lamps

19
Q

Uses of visible light?

A

-Allows us to see
-Photography
-Optical fibres (endoscope, communication)

20
Q

What are some uses of x-rays?

A

-Scanners at airports
-Medical x-ray machines.

21
Q

What are the uses and disadvantages of gamma rays?

A

-Used to sterilise food and medical equipment
-Used in cancer diagnosis
-Can cause mutations or damage to body cells. This could lead to death.

22
Q

What are the disadvantages of microwaves?

A

They can cause heating of internal tissues in the body.

23
Q

Disadvantages of Infrared radiation.

A

Can cause skin burns

24
Q

Where is the danger of electromagnetic waves

A

Danger increases with frequency.

25
Q

What are the dangers of excessive exposure to ultraviolet?

A

You could damage your eyes and the cells on the surface of your skin. This could lead to skin cancer or eyes conditions (blindness).

26
Q

What is the normal in terms of reflection and refraction?

A

A vertical imagery line which is perpendicular to the boundary.

27
Q

What happens when light is reflected off a boundary?

A

It is reflected of a smooth flat surface so that the angle of incidence is the same as the angle of reflection.

28
Q

What happens when light is refraced while passing through 2 different media?

A

-The light changes speed and direction in the new medium.
-If the medium is more dense, the light will travel slower and bend towards the normal
-If the medium is less dense, the light will travel faster and bend away from the normal

29
Q

State an equation linking angle of incidence, angle of refraction and refractive index.

A

n=sin(i)/sin(r)
i=incidence
r=refraction
n=refractive index
sin(i)/nxsin(r)

30
Q

What is the critical angle?

A

The angle of incidence which causes the angle of reflection to be 90 degrees so that the light refracts onto the boudary.

31
Q

State an equation linking critical angle and refractive index.

A

n=1/sin(c)
n=refractive index
c=critical angle
1/nxsin(c)

32
Q

What is total internal reflection?

A

When light is trying to pass from a less dense medium to a denser medium, it can be reflected back to the less dense medium if the angle of incidence is larger that the critical angle between the two media.

33
Q

Uses of total internal reflection?

A

-Endoscopes
-Periscopes
-Optical Fibres
-Cat Eye Reflectors
-Shining of diamonds

34
Q

Why type of wave is sound?

A

Longitudinal

35
Q

Range of frequencies that humans can hear?

A

Between 20-20,000 Hz

36
Q

How can you measure the velocity of sound in air with the echo clap method?

A

Clap a long distance from a wall, and record the time taken to hear the echo. Record the distance travelled, which is twice the distance between the wall and the person. Use speed= distance/ time to work out the speed

37
Q

How can you measure the velocity of sound in air by making a sound?

A

Making a sound and record how long it takes to hear it over a large distance (ie. larger than 50 m). Use an electronic timer or data logger to record the time. Use the equation wave speed = distance /time to find speed.

38
Q

How can you measure the velocity of sound in air using two microphones and a data logger?

A

The sound is made and picked up by both microphones which are placed in different places. The data logger records the time taken between each microphone ti hear the sound. This can be used to calculate the speed.

39
Q

How does sonar work?

A

Ultrasound waves are emitted they reflect off boundaries and their echoes are detected. The speed of the ultrasound is known and also the time it takes to detect the echoes. The equation distance = speed x time is used to find the distance between the ultrasound and boundary.

40
Q

How does ultrasound scanning work?

A

An ultrasound wave is sent into the patient’s body. It passes through the body and reflects off the organs and tissue. The device then uses the reflected ultrasound waves to produce an image of the foetus. Ultrasound is safe and therefore does not damage cells.

41
Q

Which property of sound waves describes the loudness of the sound?

A

Amplitude
-Higher amplitude means louder sound

42
Q

Which property describes the pitch of the sound?

A

Frequency
-Higher frequency means higher pitch

iGCSE Physics (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions