Generating electricity Flashcards
What factors can be changed in a dynamo to increase its current?
- Using a stronger magnet.
- Increasing the number of turns on the coil.
- Rotating the magnet faster.
What is an oscilloscope?
A device that displays the output of a dynamo.
What is does an oscilloscope trace show?
It shoes how the current produced by the dynamo varies with time.
What is the period of the alternating current?
The time for one complete cycle.
What does the crest of an oscilloscope wave represent?
The height of the maximum voltage.
What does the wavelength of an oscilloscope wave represent?
The length of the wave represents one cycle.
What is the equation for frequency in terms of period?
Frequency = 1 ÷ Period
Frequency is measure in …
Hertz (Hz)
Period is measured in …
Seconds (s)
What does a simple generator consist of?
A simple generator consists of a coil of wire rotating between the poles of a magnet.
What happens to the coil in the generator?
- The coil cuts through the magnetic fields as it spins.
- This produces a current in the coil.
Does the coil need to always move?
- No, the wire can remain stationary while the magnet moves.
- Note: it is the relative movement of the magnet and coil that is important.
- Generators in power stations work on the same principle.
How are fuels use in conventional power stations?
The fuels are used to heat up water.
- Water boils to produce steam.
- Steam at high pressure turns a turbine.
- The turbine drives a generator.
Where is energy lost in power stations?
- Boilers.
- Generators.
- Cooling towers.
Formula for efficiency
Efficiency = useful energy output/total energy output.
