Potential difference

• Potential difference is the “electrical pressure” which causes current to flow in a circuit
• The amount of current flowing depends on the potential difference of the circuit
• Potential difference is also known as voltage 
• It is measured in volts
• For electrons to flow in a circuit there must be a force to push them
• The force is provided by the cells
• The more cells there are the greater the pushing force
• This force or voltage is measured using a voltmeter
• A voltmeter measures the potential difference between two points in a circuit
• It does not measure the potential difference (p.d.) for the whole circuit
• The voltmeter is thus connected between the two points being measured
• Voltmeters are thus connected in parallel
• Ammeters are connected in series
• If the pushing force in a circuit is increased more electrons should flow through it

To access more topics go to the Combined Science Notes page.