1. Potential Difference vs EMF

You may previously have used the term 'voltage' but now you need to understand the difference between the e.m.f. of a supply and the p.d. 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?

  • '1 volt is the potential difference between two points when 1 joule of work is done to move a charge of 1 coulomb.' 


  • '1V is the p.d across a component when 1 joule of energy is transferred per coulomb of charge passing through the component.'


3. The Kinetic Energy of Electrons

Video text goes in here, with two lines at the end.


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.