Voltage
The potential difference or EMF across a component
1. Potential Difference vs EMF
You may previously have used the term 'voltage' but now you need to understand the difference between the EMF of a supply and the PD across a component. Please note that this analogy is not perfect, it doesn't really explain how energy can be transferred almost instantaneously or how alternating current works but it's a start...
2. The Volt and W=QV
How can you define the volt?
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'1 volt is the potential difference between two points when 1 joule of work is done to move a charge of 1 coulomb.'
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'1V is the PD across a component when 1 joule of energy is transferred per coulomb of charge passing through the component.'
3. The Kinetic Energy of Electrons
The energy gained by charged particle moving through a potential difference can be converted into kinetic energy. This is the basis of old style TVs, oscilloscopes and also particle detectors.
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4. Kirchhoff's Second Law
This will help you to understand Kirchhoff's 2nd Law when you consider the conservation of energy in a circuit.
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