Physics assessment September 2016 Flashcards Preview

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Flashcards in Physics assessment September 2016 Deck (123):
1

What are kilowatt-hours?

Units of enegry

2

Give an example of an electrical appliance that has to transfer electrical energy in to other forms?

Sound and Heat energy in a radio
Sound, heat and kinetic in a hair dryer

3

What is energy measured in?

Joules (j)

4

What is power measured in?

Watts or killowatts

5

Name 8 renewable energy sources?

Wind power
Solar Cells
Hydroelectric Power
Pumped Storage
Wave Power
Tidal Barrages
Geothermal Energy
Biofuels

6

Where does tend to flow away from?

From hotter objects to cooler surrondings

7

What 3 ways is heat transferred?

Radiation
Conduction
Convection

8

What is heat radiation?

The transfer of heat energy by infrared radiation

9

Which 2 ways involve the transfer of energy by particles?

Conduction
Convection

10

What is the main form of heat transfer in solids?

Conduction

11

What is the main form of heat transfer in liquids and gases?

Convection

12

Infrared radiation can be emitted by.....?

Solids
Liquids
Gases

13

An object can both....and.... infrared radiation

Absorb
Emit

14

The bigger the temperature difference between a body and its surroundings the....?

Faster energy is transferred by heating

15

When you heat a substance you give the particles more....

Kinetic energy

16

What is conduction of heat energy?

vibrating particles pass energy to others transferring heat

17

Why do metals conduct so well?

Free electrons

18

What is convection?

Energetic particles move from the hotter regions to the cooler ones and take their heat energy with them

19

What are convection currents?

Change in density

20

Steps in convection currents?

Particles spread and water/air expands
Hot water/air rises as its less dense
Fast particles collide with slow transferring heat
Cool water/air falls as its now more dense

21

What is reflection of light?

Is what allows us to see objects. Lights bounces of them into our eyes

22

What is the normal?

An imaginary line that's perpendicular to the surface at the point of incidence.

23

When light is travelling in the same direction reflects from an uneven surface what will the light do?

Light will reflect off at different angles

24

What rules apply when drawing a ray diagram?

The image is the same size as the object.
The object and image are the same distance away from the mirror.

25

What 3 things is the virtual image?

Laterally inverted
Same distance
Same size

26

What does laterally inverted mean?

The lefts and right sides are swapped

27

What do waves do when they reflect?

They obey the law of reflection

28

What is the angle of incidence ?

Its in between the incoming ray and the normal

29

What is the angle of reflection?

Its in between the reflected ray and the normal

30

What are waves?

They are vibrations that transfer energy from one place to another

31

Which sound waves travel through a medium?

Sound waves and seismic waves

32

What do transverse waves do?

The vibrations are at right angles to the direction of travel and energy transfer

33

What are transverse waves?

Light, water and s waves

34

What do longitudinal waves do?

The vibrations are along the same direction as the direction of travel and energy transfer.
They are parallel

35

What are longitudinal waves?

Sound waves, p waves and waves in a stretched spring

36

Longitudinal waves show what?

Areas of compression and rarefraction.
Compression=spring close together
Rarefraction=spring far apart

37

What is the amplitude?

maximum vibration from its undisturbed position. (half the height of a wavelength,bigger it is the more energy)

38

What is wavelength?

The distance between a point on one wave and the same point on the next wave.

39

What is frequency of a wave?

It is the number of waves produced each second.
Number of waves that pass a certain point each second.

40

What is V in the speed equation?

Is the wave speed in metres per second

41

What is f in the speed equation?

Is the frequency in Hertz

42

What is lambda in the speed equation?

Is the wave length in meters

43

What is refraction?

The change in direction of sound and light waves when passing across two substances with different densities

44

What is diffraction?

Spreading out of waves as they pass an object or through a gap between objects

45

When does significant diffraction take place?

When the wavelength is of the same order of magnitude as the gap

46

What is redshift?

Increasing in wavelength of light as a galaxy moves away from us

47

Distant galaxies are moving away from us, and that the further away a galaxy is...?

The faster its moving

48

Microwaves are coming from every direction in space and this is called?

Cosmic microwave background radiation
CMBR waves

49

The bigger the redshift?

faster galaxy is moving away from us
further galaxy is moving away from us

50

What is reflection?

Boncing back of waves off materials they cant easily pass through

51

What is the ionosphere?

A charged layer in the atmosphere.
Microwaves can penetrate to communicate with satellites.

52

The big bang theory?

The universe started at a very initial point and exploded

53

Heat can be transferred by?

Conduction
Convection
Radiation

54

Dark matt surfaces are better at what?

Absorbing heat energy that light shiny surfaces

55

What does radiation involve?

Electromagnetic waves

56

Poor conduction of heat are called?

Insulators

57

Metal atoms left behind are now what?

Charged metal ions

58

The hotter the metal the...

more kinetic energy the vibrations have

59

When does convection occur?

When particles with a lot of heat energy in a liquid or gass move and take the place of particles with less heat energy

60

Why do liquids and gasses expand when heated?

The particles move faster when heated, they take up more volume

61

Liquid or gas is less dense in hot areas and compared to when to when they are in cold areas, this means?

It will rise into cold areas

62

The hotter an object the more ...

infrared radiation it emits

63

What type of object radiates heat energy faster?

A thin flat object

64

Heat is lost through?

The roof
Windows
Walls
Floor
Gaps around the door

65

Ways to reduce heat loss?

Fitting carpet
Curtains
Draught excluders

66

The gap between two panes of glass is filled with what?

Air

67

Heat loss through walls can be reduced by?

Cavity wall insulation

68

What does cavity wall insulation reduce?

Air circulation inside the cavity.
Reducing heat loss by convection and conduction

69

Types of energy?

Magnetic
Kinetic
Heat
Light
Gravitational potential
Chemical
Sound
Electrical
Elastic potential
Nuclear

70

Where is nuclear stored?

Nuclei of atoms

71

The thicker the arrow in a sankey diagram...

The greater amount of energy

72

Energy cannot be created or destroyed it can only be...

Transferred from one form to another

73

What does the first transformer do?

Increases voltage

74

What does the national grid reduce?

Energy loss during transmission

75

One unit of electricity is equivalent to what?

One kilowatt used in one hour

76

Why are power stations built?

To generate electricity

77

The 1st step in a power station?

Fuel is burned to boil water to make steam

78

The 2nd step in a power station?

Steam makes a turbine spin

79

The 3rd step in a power station?

Spinning turbine turns on generator producing electricity

80

The 4th step in a power station?

Electricity goes to the transformers to produce the correct voltage

81

The energy needed to boil the water comes from where?

Fossil fuels
Nuclear fuels

82

What natural renewable ways does the generator directly drive?

Wind and wave power

83

What is a transformer?

Electrical device that changes the voltage of an alternating current

84

Name the two transformers?

Step-up transformer
Step-down transformer

85

Electricity is transferred from...

Power stations to consumers

86

Some energy is lost through the wire as?

Heat

87

The higher the current?

The more heat is lost

88

To reduce heat loss what does the national grid do?

Transmits electricity at a low current, it needs a high voltage

89

Power stations produce electricity at what?

25,000V

90

Electricity is sent through the cables at what?

400,000V
275,000V
132,000V

91

what do step-up transformers do?

Produce high voltages to transmit electricity

92

What do step-down transformers do?

Used locally, to reduce voltage to safe levels

93

House hold electricity is?

230V

94

What is the equation to work out the cost of an electrical appliance?

Energy transferred(kWh) = power (kw) x time (h)

95

What are fossil fuels?

Coal, oil and natural gas

96

How where fossil fuels formed?

By remains of living organisms

97

What do fossil fuels release when burned?

Heat energy

98

Fossil fuels are...

non-renewable

99

Name 3 disadvantages for using fossil fuels?

Their supply is limited so they will eventually run out.
Release sulphur dioxide when burned
Release carbon dioxide

100

Why is carbon dioxide bad for environment?

It adds to the green house effect.
Increases global warming

101

What is carbon capture?

Prevents carbon dioxide building up in atmosphere

102

What does carbon capture involve?

Separating carbon dioxide from waste gases

103

Carbon dioxide is stored where in carbon capture?

Stored underground or under seas

104

What are the main nuclear fuels?

Uranium and plutonium

105

What do nuclear fission reactions release?

Heat energy

106

Disadvantage to wind energy?

Wind farms are noisy.
If there is no wind electricity wont be made

107

What is a tidal barrage?

A barrier built over a river estuary

108

Name a power station which doesn't take long to start up?

Gas-fired station

109

Name a power station which takes a long time to start up?

Nuclear power station

110

Optical fibres carry what?

Information coded in light or infrared signals

111

What is an optical fibre?

Thin rod of high quality glass

112

Computer data and telephone calls can be converted into what?

Electrical signals

113

Light getting in at one end does what in an optical fibre?

Undergoes repeated total internal

114

What are endoscopes?

Images from inside the body

115

What speed do all electromagnetic waves travel at?

300,00 km/s

116

Name the electromagnetic waves?

Radio
Microwaves
Infrared
Visible
Ultra violet
X-ray
Gamma

117

Use of radio waves?

Communication

118

Use of Micro waves?

Micro-waves

119

Use of infra-red?

Remotes
Heat
Cooking

120

Use of visible light?

Fibre optics
Endoscopes

121

Use of ultra violet?

Forgery marking
Cancer

122

Use of x rays?

Medical images
Cancer

123

Use of gamma rays?

Radio therapy
Cancer