Generation and transmission of electricity Flashcards
What is electric current?
The flow of charge round a circuit
Does alternating change direction?
Yes
Does direct current change direction?
No
What induces a voltage?
Moving a magnet in a coil of wire
What are the 4 factors that affect the size of the induced voltage +current
- Strength of magnet
- Number of turns in coil
- Area of coil
- speed of movement
What are the 6 alternatives to burning fossil fuels?
- Hydroelectricity
- Wave power
- Tidal power
- Wind power
- Solar power
- Geothermal energy
What is hydroelectricity?
Building dams and flooding valleys
What is wave power?
Wave powered turbines
What is tidal power?
Using moon+ suns gravity
What is wind power?
Wind turbines
What is solar power?
Electrical current from sunlight
What is geothermal energy?
Heat from underground
Why do renewable resources usually have the lowest running costs?
1.Because there is no fuel involved( except biomass)
What two types of renewable resources effect the surrounding habitats?
- Hydroelectric
2. Tidal
How does hydroelectricity work?
How does it impact the environment?
What’s an advantage of it?
- Involves flooding a valley by building a big dam
- Rainwater is caught and goes out through turbines
- Big impact on environment due to valleys flooding and possible loss of habitat
- Big advantage is that its a n immediate response to electricity demand- more water let out through turbines to make electricity
How does wave power work?
Whey are they unreliable?
- Waves provide up and down motion which drives generator
2. Wave power unreliable, because waves die out when wind drops
How do tidal barrages work?
- Big dams across river estuaries, with turbines in them
2. As tide comes in fills up estuary, this water allowed out of turbines
How do wind turbines work?
What are the disadvantages?
- Each turbine has own generator so electricity made directly from wind turning the blades, which turn the generator
- Spoil the view
- Noisy
- Only work when its windy
How does Geothermal energy work?
What is a drawback of Geothermal energy?
- Water pumped down to hot rocks, returns as steam to drive generator
- Big setup costs
What does a step up transformer do?
Increase voltage, decrease current
What does a step down transformer do?
Decrease voltage, increase current
What is risk with flying a kite next to a power line?
- Electrocution due to high voltage
