Generation and transmission of electricity Flashcards
what is current
the rate of flow of charge
what is voltage
an electrical pressure giving a measure of the energy transferred
what is power, what is it measured in
the energy transferred per second and measured in watts
what are the advantages of methods of Large scale electricity production using a variety of renewable resources
1) generating electricity using renewable resources does not usually cause pollution
2) there are no fuel costs
what are the disadvantages of methods of Large scale electricity production using a variety of renewable resources
1) does cost money to build the machinery to generate electricity
2) wind turbines spoil the view
3) reservoirs used for hydroelectricity flood valleys, and tidal barrages change the environment in river estuaries. both change habitats and can harm wildlife
4) most form of renewable energy are not available all the time
what are the factors affecting the generation of electric current by induction
1) the strength of the magnet
2) number of turns on the coil
3) area of the coil
4) speed of the movement
what do generators do
supply current which alternates in direction
what is the difference between direct and alternating current
direct current always flows in the same direction. alternating current changes direction many times each second. generators produce alternating current because each slide of the coil foes up through the magnetic field and then comes down again. this induces a current in one direction then in the opposite direction
what can a transformer do
can change the size of an alternating voltage
why is electrical energy transmitted at high voltage
as it improves the efficiency by reducing heat loss in transmission lines
Explain where and why step-up and step-down transformers are used in the transmission of electricity in the National Grid
step up transformers are used to increase the voltage as it leaves the power station and before the electricity is transmitted.
step down transformers take electricity from the power lines and reduce it to safer voltages again before it goes into homes
Describe the hazards associated with electricity transmission
the voltage is high enough to kill you if you touch a transmission line, or if a kite string or carbon fishing pole touches the line.
what is energy from the mains supply is measured in
kilowatt-hours
what are the advantages of the use of low-energy appliances
cheaper to run, saving energy and resources,
what is payback time
the time it takes to save the amount of money you had to spend to start with.
