Electricity Quiz Flashcards
Define current
the rate of flow of charge round a circuit
Define voltage
the electrical pressure giving a measure of the energy transferred
Define power
energy (j) transferred per second.
measured in watts
How do you work out how much energy an appliance uses?
Measure how many watts it uses per second
Children= energy
A slide slides down 15 children in 5 seconds.
State the energy and the power.
Power= 3 Watts Energy= 3 joules per sec
State the units used in energy equations and cost equations/ electricity meters
energy e. meters/ main supply
energy j kWh
power W kW
time s Hrs
What can change the a.c size on the national grid
A transformer, up for efficient transmission and then down for safety and usability
Advantages of large scale electricity production using renewable sources, GO
Never run out
Less damaging to the environment
Control supply speed (tidal barrages)
Disadvantages of large scale electricity production using renewable sources, GO
Unreliable, depend on weather (Wave power)
Not always available (solar cells)
Loss of habitat (hydro e.)
High initial costs (hydro e.)
Name the factors that can affect the size and direction of induced current
The strength of the magnet
The area of the coil
The number of turns on the coil
The speed of the movement
How do you induce a voltage?
Change the magnetic field by
Putting magnet through coil of wire
Or
Keep magnet fixed, and rotate the coil
Whats the difference between a.c and d.c?
A.c reverses its direction back and forth
D.c always flows in the same direction
