# Electrical xircuits

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• Electrical charge and current
• Direct current
• Flow of electrons consistently in one direction
• electrons are negatively charged particles
• Transfer energy through wires as electricity
• Alternating current
• direction of electron flow continually reverses
• Current
• Q=I(times)T
• How much charge has moved if a current of 13 A flows for 10 s?
• Q=13 (times) 10
• 130C
• Current in a series circuit
• Potential difference
• a measure of how much energy is transferred between two points in a circuit
• to measure the potential difference a voltmeter must be placed in parallel
• also known as voltage (measured in volts
• potential difference=energy divided by change
• Potential difference= current (times) resistance
• V=I (times) R
• Resistance
• What is the potential difference if a current of 2A flows through a resistance of 40 ohms
• V=I(times)R
• V=2(times)40
• V=80V
• Series Circuit
• an electron will pass through every component on its way round a circuit
• if a bulb is broken the current can't flow through a circuit. If one bulb is out they all go out
• I1+I2=I3
• Potential difference in a series circuit
• the current transfers energy from the power supply to the components
• all the source energy is shared between components
• potential difference measures changes in energy
• Parallel Circuit
• electrical components are connected alongside one another forming extra loops
• Since there are multiple loops, the current will split as it leaves the cell
• If multiple ammeters are placed in different parts of the circuit it will show where the current splits
• I1=I2+I4=I3
• an electron will not pass through every component in a parallel circuit
• If one bulb is broken then the current will still be able to flow through the other loop of the parallel circuit