physics unit 1

?
  • Created by: hanlc3006
  • Created on: 11-12-16 09:21
what is renewable energy
energy from wind, wavs and tides that can never be used up
1 of 85
how can we use the wind to generate electricity
the energy from the wind and water is used to drive turbines directly.
2 of 85
what happens in a wind turbine
the wind passing over the blades, makes them rotate and drive a generator at the top of a narrow tower
3 of 85
how do waves generate electricity
by turning a floating generator
4 of 85
what happens at a hydroelectric power station
at a hydroelectric power station, water is collected in a reservoir. the water us allowed to flow downhill and turn turbines at the bottom of the hill
5 of 85
what happens in a pumped storage system
surplus electricity is used, at times of low demand , to pump the water back up the hill to the top reservoir. the means that the energy is stored. then at times of high demand the water is released to fall through the turbines
6 of 85
how can we use wave power to generate electricity
we can use the movement of the waves on the sea to generate electricity. the movement drives a floating turbine that turns a generator. then the electricity is delivered to the grid system on shore by a cable
7 of 85
how can we use tidal power to generate electricity
the level of the sea around the coastline rises and falls twice each day. these changes in sea peel are called tides. if a barrage is built across a river estuary, the water at each high tide can be trapped behind it.
8 of 85
solar energy from the sun travels through space to the Earth as what
electromagnetic radiation
9 of 85
what do solar cells do
they transfer solar energy directly into electricity
10 of 85
what can we use large solar cells to form what
solar panels
11 of 85
water flowing through a solar heating panel is...
directly heated by energy from the sun
12 of 85
what does a solar power tower use
it uses thousands of mirrors to reflect sunlight onto a water tank to heat the water and produce steam
13 of 85
how is geothermal energy produced
it is produced inside the earth by radioactive processes and this heats the surrounding rocks
14 of 85
in volcanic or other suitable areas what is done to create geothermal energy
very deep holes are drilled and clod water is pumped down to the hot rocks. there it is heated and comes back to the surface as steam. the steam is used to drive turbines that turn generators and so electricity is produced
15 of 85
what happens in power stations
water is heated to produce steam, the steam drives a turbine, which is coupled to an electrical generator that produced the electricity
16 of 85
what does energy come from, in power stations
they can come from coal, oil or gas. fossil fuels are obtained from long-dead biological materials
17 of 85
what happens in some gas-fired power stations
hot gases may drive the turbine directly. a gas fired turbine may be switched on very quickly
18 of 85
what is a biofuel
a biofuel is any fuel obtained from living or recently living organisms. some biofuels can be used in small-scale, gas-fired power stations. biofuels are renewable sources of energy
19 of 85
what happens in a nuclear power station
the fuel is uranium or sometimes plutonium. the nucleus of the uranium atom can undergo a process called nuclear fission. there are lots of uranium nuclei so lots of fission reactions take place, releasing lots of energy.
20 of 85
burning fuels produce what
greenhouse gases that cause global warming
21 of 85
what does nuclear fuels produce
radioactive waste
22 of 85
what can renewable energy resources affect
they can affect plant and animal life
23 of 85
what does the national grid distribute
electricity from power stations to our homes
24 of 85
how are the cables carried in the national grid
they are carried long distances across the countryside supported by overhead pylons. in towns and close to homes the cables re buried underground
25 of 85
what is the national grids voltage
132000 v or more
26 of 85
what voltage do power stations produce
25000 v
27 of 85
in power stations, how is electricity generated at a particular voltage
the voltage is increased by step-up transformers before the electricity is transmitted across the national grid. this is because transmission at high voltage reduced the energy wasted in the cables
28 of 85
what are step-down transformers used for
to reduce the voltage to 230v for use in homes and offices
29 of 85
what is base load demand
a constant amount of electricity is provided by nuclear , coal-fired and oil-fired power stations
30 of 85
what do nuclear, fossil-fuel power stations use to contribute to future energy supplies
they uses carbon capture and renewable energy
31 of 85
what do use waves for
to transfer energy and to transfer information
32 of 85
what do transverse waves do
they vibrate at right angles to the direction of energy transverse waves
33 of 85
what do longitudinal waves do
they vibrate parallel waves to the direction of energy tansfer. a sound wave is longitudinal wave
34 of 85
what are electromagnetic waves
there are no particles moving in an electromagnet wave, as these waves are oscillation in electric and magnetic fields. so all electromagnetic waves are transfer waves
35 of 85
what are mechanical waves
e.g.waves on springs and sound waves, travel through a medium (substance). mechanical waves may be transverse or longitudinal
36 of 85
what is the amplitude of a wave
it is the height of the wave crest or the depth of the wave trough from the position at rest
37 of 85
what is the wavelength of a wave
it is the distance from one crest, or from one trough to the next trough
38 of 85
what is the frequency of a wave
it is the number of waves crest passing a point in one second.
39 of 85
what is the unit for frequency
hertz
40 of 85
what is the incident ray
it is the ray that goes towards the mirror.
41 of 85
what is the reflected ray
it is the one coming away from the mirror
42 of 85
what is the normal line
it is the point where the incident ray hits the mirror
43 of 85
what is the angle of incidence
it is the angle between the incidence ray and the normal
44 of 85
what is the angle if reflection
it is the angle between the reflected ray and the normal
45 of 85
what is the rule of the waves
the angle of incidence is equal to angle of reflection
46 of 85
the image in a plane mirror is...
the same size as the object, upright, the same distance behind the mirror as the object is in front, virtual
47 of 85
what is a real image
it is the one that can be formed on a screen, because the rays of light that produce the image actually pass through it
48 of 85
what is a virtual image
it cannot be formed on a screen, because the rays of light that produce the image only appear to pass though it
49 of 85
when can waves change speed
when they come across a boundary between different substances. the wavelength of the wave also changes but the frequency stays the same
50 of 85
refraction is what
the change of direction of a light ray she it passes across a boundary between 2 transparent substances
51 of 85
the change in speed does what
causes a change in direction
52 of 85
when light enters a more dense substance such as air to glass what happens
it slows down and changes direction to the normal
53 of 85
when light enters a less dense substance such as glass to air what happens
it speeds up and the ray changes direction aways from the normal
54 of 85
if a wave travels along a normal what happens
then it will it not change direction
55 of 85
what are the most refracted colours and least refracted colours
violet - red
56 of 85
what is dispersion
when a ray of white light is shone onto a triangular glass prism we can see this because a spectrum is produced
57 of 85
what is diffraction
is it the property of all waves. it is the spreading out of waves when they pass through a gap or round the edge of an obstacle
58 of 85
the greater the diffraction...
the narrower the gap
59 of 85
what happens f the radio waves of not diffract enough...
when they go over hills, radio and TV reception will be poor
60 of 85
what is sound caused by
mechanical vibrations in a substance and travels as a wave
61 of 85
what can sound travel through
liquids, solids and gases. they usually travel fastest through solids
62 of 85
what can't sound travel through
vacuum (space)
63 of 85
what wave are sound waves
longitudinal waves
64 of 85
what is the range the human ear can hear
20hz - 20000hz
65 of 85
what are reflections of sounds called
echoes
66 of 85
sound waves can be...
refracted and diffracted
67 of 85
the pitch of notes increase when...
the frequency of the sound waves increase
68 of 85
the difference in waveform can be shown on what
oscilloscope
69 of 85
what is the electromagnetic spectrum
gamma rays, x-rays, ultraviolet, visible, infrared. microwaves, radiowaves
70 of 85
all electromagnetic waves can travel through what...
space
71 of 85
the higher the frequency of an electromagnetic wave...
the more energy it transfers
72 of 85
what do microwaves produce
wavelengths that are able to pass through the atmosphere
73 of 85
why are microwaves used
to send signals to and from the satellites and within mobil phone networks
74 of 85
what do radio waves transmit...
radio and transit raido and tv programs and carry mobile phone signals
75 of 85
what are optical fibres
they are very thin fibres that ar eased to transmit signals by light and infrared radiation
76 of 85
what is doppler effect
the wavelength and frequency of the waves detected by the observer will have changed from the original produced by the source
77 of 85
what happens when the source moves away from the observer
the observed wavelength increases and the frequency decrease
78 of 85
what happens when the source moves towards the observer
the wavelength decreases and the frequency deceases
79 of 85
what is the red shift effect
light observed from distant galaxies has been shifted towards the red end of the spectrum. the frequency has decreased and the wavelength increased
80 of 85
the further away from the galaxy ...
the bigger the red-shift
81 of 85
how is the whole universe expanding
all the distant galaxies are moving away from each other
82 of 85
what was the big bang
a massive explosion from a very small initial point
83 of 85
what is cosmic microwave background
it is the electromagnetic radiation created just after the big bang
84 of 85
if the universe began with a big bang then...
high energy gamma radiation would have been produced . as the universe expanded this would have become lower energy radiation
85 of 85

Other cards in this set

Card 2

Front

how can we use the wind to generate electricity

Back

the energy from the wind and water is used to drive turbines directly.

Card 3

Front

what happens in a wind turbine

Back

Preview of the front of card 3

Card 4

Front

how do waves generate electricity

Back

Preview of the front of card 4

Card 5

Front

what happens at a hydroelectric power station

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Electricity resources »