**Electric circuits

• Insulator


  Material that doesn't easily allow electricity / heat to pass through it
• Conductor


  Material which allows electricity/heat to flow through due to less resistance
• Electric current


  Measured in amps (A)
• Flow of electricity = current
• Resistance


  A measure of how hard it is for electrons/current to flow around a circuit
• The more components in a circuit, the more opposition there is to the flow of the current
• Resistance (R)


  Measured in OHMS (Ω)
• The larger the number of ohms, the greater the resistance
• Static electricity


  Created when materials are rubbed against each other and there is a transfer of electrons, making the materials 'charged'
• The materials have to be insulators so the charge can build up and not be conducted
• Negatively charged


  Gained electrons
• Positively charged


  Lost electrons
• Opposite charges

  Attract
• Like charges

  Repel
• Current can be measured using an ammeter, which must be connected in series with the component being tested.
• Voltage is measured by connecting a voltmeter across the ends of the component being tested.
• Resistance is calculated from Ohms law (current x voltage = resistance)
• Ammeter measures current flow through a circuit or part of it
• Voltmeter measures potential difference between two points in a circuit
• Ohm's Law states that the current flowing through a conductor is directly proportional to the potential difference applied across its ends
• potential difference is the work done per unit charge flowing through a component in a circuit