Flashcards in Unit 1B - Electricty and Waves Deck (155):
Will non renewable energy resources or renewable energy sources run out one day?
Non renewable energy resources
Name four non renewable energy resources?
Coil, oil, natural gas and nuclear fuels
Do non renewable or renewable energy resources do more damage to the environment?
Which type of energy resource do we get most if our energy from?
Non renewable energy resources
Name eight renewable energy resources?
Wind, waves, tides, hydroelectric, solar, geothermal, food and biofuels
How do we use fossil fuels (three of the non renewable energy resources) to create electrical energy?
The fossil fuel is burned in a furnace, this converts the stores chemical energy into heat energy. The heat energy is used to heat water to produce steam. The steam turns a turbine converting the heat energy into kinetic energy. The turbine is connected to a generator which converts the kinetic energy into electrical energy
How are nuclear fuels used to create energy?
The nuclear fission of uranium or plutonium to creat heat to make steam to drive the turbines and so on.
What power station takes the longest and shortest amount of time to set up?
Longest - nuclear
Shortest - natural gas
Where do you place windmills so that they get a lot of wind?
In exposed places like on moors or round coasts
How does a wind turbine generate electricity?
The wind turns the blade, which turn the turbine which is connected to a generator converting the kinetic energy into electrical energy
What are four advantages of wind power?
1.) no pollution
2.) no fuel costs
3.) minimal running costs
4.) no permanent damage to environment - you can remove them.
What are five disadvantages of wind power?
1.) spoil the view
4.) impossible to increase supply when there is an increase in demand
5.) high initial costs
How many wind turbines do you need to replace one coal fired power station.
How do solar cells generate electricity?
They generate electric current directly from sunlight.
Where is solar power often used?
In remote places where's there isn't much choice like electrical road signs and satellites.
What are four advantages of solar cells?
1.) no pollution
2.) reliable in sunny countries
3.) energy is free
4.) running costs are almost free.
What are three disadvantages of solar cells?
1.) only works in daytime.
2.) High initial costs.
3.) not practical to connect them to the national grid.
How do Hydro electric power stations generate electricity?
Falling water turns a turbine which is connected to a generator which converts kinetic energy into electrical energy.
What are four disadvantages of hydro electric power?
1.) big impact on the environment.
2.) loss of the habitat.
3.) reservoirs look unsightly when they dry up.
4.) high initial costs.
What are four advantages of hydro electric power?
1.) No pollution
2.) Can increase supply with demand.
3.) No fuel required.
4.) Minimal running costs.
How does pumped storage generate electricity when it is needed?
There is surplus electricity at night as demand is low so the pump storage system uses the spare night time electricity to pump water up to a higher reservoir. This can be released during high demand to generate electricity.
What is the difference between pumped storage and hydro electric power?
Hydro electric power generates electricity whereas pumped storage system stores energy which has already been generated.
How do wave powered turbines generate electricity?
As water moves up into it air is forced upwards turning a turbine which is connected to a generator which converts kinetic energy into electrical energy.
What are three advantages of wave power?
1.) no pollution
2.) no fuel costs
3.) minimal running costs
What are four disadvantages of wave power?
1.) spoil the view
2.) hazardous to boats
3.) fairly unreliable
4.) high initial costs
How do tidal barrages generate electricity?
They hold back the tide and then release it through the barrages. The moving water drives a turbine which is connected to a generator which converts kinetic energy into electrical energy.
What are five advantages of tidal barrages?
1.) no pollution
2.) pretty reliable as there is a tide twice a day
3.) Excellent for storing energy for peak demands
4.) no fuel costs
5.) minimal running costs
What are five disadvantages of tidal barrages?
1.) prevent free access by boats
2.) spoil the view
3.) alter the habitat
4.) height of the tide is variable so lower tides would supply significantly less energy
5.) high initial costs
How does geothermal energy generate electricity?
Hot water and steam rise from the earth from hot rocks. Steam is used to drive a turbine and the turbine is connected to a generator which converts kinetic energy into electrical energy.
Why is geothermal only possible in certain areas?
Its only possible in volcanic areas where hot rocks lie near to the surface.
What is the source of the heat in geothermal energy?
The slow decay of various radioactive elements including Uranium.
What are two disadvantages of geothermal energy?
1.) cost of building power plant is quite high compared to the amount of energy that is produced
2.) aren't many suitable locations
What are two advantage of geothermal energy?
1.) free energy
2.) no real environmental problems
What are bio fuels made from?
plants and waste.
How are bio fuels used to generate electricity?
They are burnt to convert stored chemical energy into heat energy which is used to heat water into steam which drives a turbine which converts the heat energy into kinetic energy which is connected to a generator which converts kinetic energy into electrical energy.
What does burning fossil fuels release into the atmosphere and add to?
CO2 which adds to the greenhouse effect which contributes to global warming.
What gas that is released by burning coal and oil causes acid rain?
How can acid rain be reduced?
By taking out the sulphur before the fuel is burned or by cleaning up emissions.
What does coal mining make a mess off?
What is an effect of oil spillages?
It causes serious environmental problems affecting mammals and birds.
What are three disadvantages of nuclear power?
1.) nuclear waste is dangerous and difficult to dispose of
2.) carries the risk of a major catastrophe
3.) overall cost is high due to cost of the power plant and the final decommissioning.
What are two advantages of nuclear power?
1.) nuclear fuel is relatively cheap
2.) it doesn't produce greenhouse gases
What are two advantages of bio fuels?
1.) relatively quick
2.) carbon neutral
What are four disadvantages of bio fuels?
1.) large areas of forest have been cleared to grow them
2.) resulting in loss of natural habitat
3.) decay and burning of vegetation leads to increase CO2 and methane emissions
4.) limits the land available to grow crops
Why is Carbon Capture and Storage used?
Reduces the amount of CO2 building up in the atmosphere and reduces the strength of the greenhouse effect.
Where is the captured carbon released?
Pumped into empty gas fields and oil fields like those in the North Sea.
When building a new power station what five factors do you need to consider?
1.) Set up and running costs
2.) set up and decommissioning time
3.) reliability issues
4.) environmental issues
5.) location issues.
What are three reasons that many of the old coal and oil fired power stations are being replaced by gas fired power stations?
1.) they are quick to set up
2.) there is a lot of gas left
3.) they don't pollute as badly
Between renewable and non renewable power stations which ones are more expensive to set up?
renewable resources need bigger power stations and bigger power stations are more expensive to set up.
Why are nuclear reactors and hydro electric dams more expensive to set up?
They require huge amounts of engineers.
Why are renewable sources often unreliable and what it the exception to this?
They depend on the weather, the exception is tidal and geothermal because they don't.
Name seven environmental issues to do with energy resources.
1.) atmospheric pollution
2.) visual pollution
3.) using up finite resources
4.) noise pollution
5.) disruption of habitats
6.) disruption of leisure activities
7.) other problems like danger of nuclear explosions or hydro electric dams bursting.
Why do renewable energy resources have lower running costs?
There is no fuel involved.
What location must solar power be in?
Anywhere along as it is sunny.
What location must gas power stations be in?
Anywhere there is piped gas.
What location must hydro electric power stations be in?
Hilly, rainy places with floodable valleys.
What location must oil power stations be in?
Near the coast as oil is transported by sea.
Where must wave power stations be?
On the coast/in the sea.
What location must coal fired power stations be in?
Near coal mines.
What location must nuclear power stations be in?
Away from people in case of disaster and near water for cooling.
Where must geothermal power stations be located?
Only in places where hot rocks are near the earth's surface.
What does the national grid do?
It takes electrical energy from power stations to where it is needed in homes and industry.
Why does the national grid use a high voltage and low current?
A high current means you lose a load of energy through heat so it cheaper to boost the voltage and keep the current low.
What is used to increase and decrease the voltage?
Step up and step down transformers.
What are the two different ways to transmit electricity?
Underground or overhead cables.
Between overhead and underground cables which one has a higher set up cost?
Between overhead and underground cables which one has a higher maintenance cost?
Between overhead and underground cables which ones when faulty are easier to access?
Between overhead and underground cables which one looks uglier?
Between overhead and underground cables which one is affected by weather?
Between overhead and underground cables which one is more reliable?
Between overhead and underground cables which one is easier to set up?
Between overhead and underground cables which one has more disturbance to land?
How can supply of electricity be increased?
Opening more power stations
How can demand be reduced?
Using more energy efficient appliances and being more careful not to waste in the energy in the home or at work.
Supply must meet?
What is the top of a wave called?
What is the bottom of a wave called?
What is amplitude?
The displacement from rest position to crest.
What is wave length?
A full cycle of the wave from crest to crest.
What is frequency?
The number of complete waves passing a certain point per second.
What is frequency measured in?
What are the two different types of wave?
What is a transverse wave?
Where the vibrations of the wave are perpendicular to the direction of energy transfer.
Name four examples of transverse waves?
2.) all electromagnetic waves
3.) ripples on water
4.) a slinky spring wiggled up and down.
What is a longitudinal wave?
Where the vibrations of the wave are parallel to the direction of energy transfer of the wave.
Name four longitudinal waves?
1.) sound waves
2.) ultrasound waves
3.) shock waves
4.) a slinky spring when you push the end
In a longitudinal wave what is one wavelength.
The difference between two compressions.
What replaces crest and trough in longitudinal waves?
Compressions and rarefactions
When a wave meets an obstacle their direction of travel can be changed by what three things?
What does reflection of light let us do?
What is reflection?
When light rays bounce off the surface of an object.
If light is travelling in the same direction and hits an uneven surface what are the angles of reflection like?
What is the normal?
A perpendicular line to the mirror
What is the difference between angle of incidence and angle of reflection?
The angle of incidence is the angle between the incident light ray and the normal whereas the angle of reflection is the angel between the reflected light ray and the normal.
What four things do you need to remember about how an image is formed on a plain mirror?
1.) the image is the same size as the object
2.) it is as far behind the mirror as in front.
3.) it is virtual and upright
4.) the image is laterally inverted
What is diffraction?
When waves spread out at edges when they pass through a gap or pass an obstacle.
What is the amount of diffraction depend on?
The size of the gap relative to the wave length of the wave.
If there is a narrow gap and a long wave length how much does the wave spread out?
What is refraction?
When waves change speed when they meet a new boundary.
How does refraction work?
If a wave goes from a less dense medium to a denser one at an angle the wave length becomes shorter and changes direction - it is refracted.
What happens if a wave goes from a less medium to a denser one and wave is travelling along the normal what will happen?
It will change speed and not become refracted.
What does EM wave stand for?
What are the seven EM waves?
Radio waves, microwaves, infrared, visible light, ultraviolent light, x rays, gamma rays
How do you remember the different EM waves?
Reindeer Meat Is a Very Unusual Xmas Gift!!!
As you go up from radio waves to gamma rays does the wave length increase or decrease?
Between infra red and ultraviolet which one has a smaller wave length
EM waves with short wave lengths have what frequency?
Do EM waves travel at the same speed?
What is the speed of an EM wave in a vacuum?
3 x 10 to the power of 8 m/s
Why are EM waves used for different purposes?
Because they have different properties.
Why can long wave radio waves be transmitted from London to half way around the world but not short wave radio waves?
Long wave length defract so they can bend around the curved surface of the earth.
Long wave radio waves can also be defracted around?
Hills and tunnels.
Why can short wave radio signals be received a long distance from the transmitter?
Because they are reflected from the ionosphere.
Microwaves are used for?
Satellite communications and mobile phones.
Why do you use microwaves for satellite comms and mobile phones instead of radio waves?
Microwaves can pass easily through the earth's watery atmosphere.
Why do people think using mobile phones may start to cook you?
Mobile phone calls travel as microwaves, some wave lengths of microwaves are absorbed by water molecules and heat them up if this water is inside yourself then you cook.
What three things are microwaves used for by remote sensing satellites?
1.) see through clouds and monitor oil spills.
2.) track movement of icebergs.
3.) see how much rain forest has been chopped down.
What are infra red waves used for?
Wireless remote controllers and optical fibres.
How do remote controls work?
By emitting different patters of infra red waves to send different commands to the tv.
How much distance can optical fibres carry data over?
Very long distances.
How do optical fibres use infrared?
Pulses of infrared are reflected from the sides of a very narrow core from one end of the fibre to the other.
What is visible light useful for?
What does a camera use a lens for?
To focus visible light onto a light sensitive film or electronic sensor.
What does a lens aperture control?
It control how much light enters the camera.
What does the shutter speed determine?
How long the film or sensor is exposed to light.
What type of wave are sound waves?
When do we hear sound?
When the vibrations reach our eardrums.
What are sound waves caused by?
How does the speed of sound vary between liquids, solids and gases?
Travels faster in solids than in liquids and faster in liquids than gases.
Can sound travel in space and why?
It can't because there are no particles to vibrate.
Which two can sound waves do... diffract, refract or reflect?
reflect and refract
What are echoes?
Reflected sound waves.
Why do you hear a delay between the original sound and the echo?
Because the echo sound waves have to travel further so they take longer to reach your ears.
How do sound waves refract when they enter a different medium?
As they enter a denser material they speed up.
How does a high frequency and low frequency affect the pitch?
High frequency sound waves sound high pitched, low frequency sound waves sound low pitched.
The loudness of the sound depends on?
How does the amplitude affect the sound?
The bigger the amplitude the louder the sound.
Is the universe contracting or expanding?
How can you tell that the universe is expanding?
Light from distant galaxies are at a slightly lower frequency than they should be, they have shifted towards the red end, this is called red shift. Because of the Doppler effect it shows the universe is expanding.
What is the Doppler effect and how does this affect sound?
As a source of a sound moves toward you the frequency will seem higher and its wavelength will seem shorter giving it a higher pitch and as that object moves away the frequency will seem lower and it's wavelength will seem longer giving it a lower pitch.
How does the Doppler effect prove that the universe is expanding?
The light from the galaxies has a lower frequency and a higher wavelength than it should do, this suggests that they are moving away. More distant galaxies have greater red shifts than nearer ones.
What does the fact that more distant galaxies have greater red shifts than nearer ones show?
Distant galaxies are moving away from us faster than nearer ones.
What is thought to be the origin/start of the universe?
Da Big Bang
What is the Big Bang theory?
All matter and energy in the universe must have been compressed into a very small space then exploded from that single point and started expanding.
How long ago was the big band thought to have happened?
14 billion years ago.
What is the name of another theory other than the big band to try and explain the origin of the universe?
The steady state theory
What is the steady state theory?
The universe has always existed as it is now and will always do, the universe appears pretty much the same everywhere
How does the steady state theory explain the universes expansion?
Matter is being created in space so the universe expands.
What is the biggest problem with the steady state theory?
The discovery of cosmic microwave gave strong evidence for the big bang.
Where did cosmic microwave background come from?
Just after the big bang while the universe was still extremely hot, everything in the universe emitted very high frequency radiation. As the universe expanded it has cooled and this radiation has dropped in frequency and is now seen as microwave radiation.
What does the cosmic microwave background radiation state?
There is low frequency EM waves coming from all directions and parts of the universe.
What are two things wrong with the big bang theory?
1.) predictions of why the universe is expanding means it should be slowing down and it's not.
2.) no explanation for what actually caused the explosion and what conditions were like beforehand.
How will the big bang be changed in the future?
It will be adapted as new evidence is found to account for it's weaknesses.