Flashcards
Fuels for power
Cards in this deck (24)
- 1What does an electric current involve?It involves a flow of electric charge which transfers energy from the battery or power supply to the components in the circuit, e.g. a light bulb.
- 2What does the rate of energy transfer determine?It determines the power of the component or device.
- 3What is the power of a component or device measured in?It is measured in joules per second or watts (W). Where 1 watt is the transfer of 1 joule of energy in 1 second.
- 4Do power stations generate electricity all the time?Yes, because it is not easy to switch a power station on and off.
- 5What are peak times?The time of the day when the electricity companies charge more for electricity due to millions of people wanting it.
- 6What are off peak times?The time of night when too few people are using electricity.
- 7What could off peak electricity be used for?Heating up water and storage heaters.
Powering washing machines and dishwashers running at night.
etc. - 8What is the advantage and disadvantage for the electricity-generating companies when selling at off peak times?Advantage: Don't need to turn off the power station and they can sell the electricity they are generating.
Disadvantage: they make less profit. - 9What is the advantage and disadvantage for the consumer using electricity in off peak times?Advantage: cheaper.
Disadvantage: it is inconvenient to run appliances at night because of the noise. - 10What does an electricity meter show?It shows a count of units. These units represent kilowatt hours (kWh), which are a measure of how much electrical energy has been used.
- 11What does the number of units of electricity used by an appliance depend on?The power rating in kilowatts of the appliance.
The time in hours that the appliance is switched on for. - 12How do you calculate the cost of using a device?(energy supplied) Number of kWh = power rating (kW) * Time (h).
Total cost = Number of kWh * Cost of one kWh - 13What is the kilowatt hour a measure of?It is a measure of how much electricity has been used. It is also a measure how much electrical energy has been supplied
- 14To supply electricity to our homes efficiently, what does the electricity go across? and what is the current fed through?The electricity travels across the national grid to our homes, and the current is fed through transformers.
- 15What is the 1st transformer called and what does it do?It is a step up transformer.
It :
decreases the electrical current.
Increases the voltage.
It means that every electron in the wire carries more energy, BUT there are less of them in the wire. This means that less heat is produced so less energy is wasted in the cable. The process of transmission is therefore more efficient and less costly. - 16What is the 2nd transformer called and what does it do?It is called a step-down transformer.
It:
decreases the voltage.
Increases the electrical current.
This means that electricity can now be used in the home. - 17What are the advantages of using fossil fuels?Enough reserves for short to medium term.
Relatively cheap and easy to obtain.
Coal, oil and gas-fired power stations are flexible in meeting demand and have a relatively short start-up time.
Burning gas produces very little sulphur dioxide. - 18What are the disadvantages of using fossil fuels?Produces carbon dioxide - causes global warming, and sulphur dioxide (except burning gas) - causes acid rain.
Removing sulphur dioxide and carbon dioxide to reduce global warming, adds to the cost.
Oil has a risk of spillage and pollution.
Expensive pipelines and networks are often required to transport oil and gas to the point of use. - 19What are the advantages of using biomass, e.g. wood, straw, manure?It is renewable.
Can be burned to produce heat.
Fermenting biomass produces methane, which can be burned. - 20What are the disadvantages of using biomass, e.g. wood, straw, manure?Produces carbon dioxide, which damages the environment.
Large area needed to grow trees which could be used for other purposes, e.g. growing food. - 21What are the advantages of using Nuclear fuel, e.g. uranium?Cost and rate of fuel use is relatively low.
Can be situated in sparsely populated areas.
Nuclear power stations are flexible in meeting demand.
Does not produce carbon dioxide or sulphur dioxide.
High stocks of nuclear fuel.
Can reduce the use of fossil fuels. - 22What are the disadvantages of using Nuclear fuel, e.g. uranium?Radioactive material can stay dangerously radioactive for thousands of years and can be harmful.
Storing radioactive waste is very expensive.
Building and decommissioning nuclear power stations are costly.
Comparatively long start up time.
Radioactive material could be emitted.
Pollution from fuel processing.
High maintenance costs. - 23What are the advantages of using Renewable sources, e.g. wind, tidal, hydroelectric, solar?No fuel costs during operation.
No chemical pollution.
Often low labour costs.
Do not contribute to global warming or produce acid rain.
Produce clean electricity.
Can be constructed in remote areas. - 24What are the disadvantages of using Renewable sources, e.g. wind, tidal, hydroelectric, solar?With the exception of hydroelectric, they produce small amounts of electricity.
Take up lots of space and are unsightly.
Unreliable (apart from hydroelectric), depend on the weather and cannot guarantee supply on demand.
High initial costs to build and install.
High maintenance costs.
Produces pollution when in the manufacturing process.
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- GCSE Physics (P2) Flashcards on Fuels for power, created by Rebecca Smith on 24/02/2017.
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