Parallel circuits
In parallel circuits, A device in an electric circuit, such as a battery, switch or lamp. are connected alongside one another forming extra loops.
Circuit rules
An Subatomic particle, with a negative charge and a negligible mass relative to protons and neutrons. will not pass through every component on its way round the circuit. If one of the bulbs is broken then Moving electric charges, eg electrons moving through a metal wire. will still be able to flow round the circuit through the other loop. If one bulb goes out, the other will stay on.
Current in parallel
Since there are different loops, the current will split as it leaves the cell and pass through one or other of the loops. An A device used to measure electric current. placed in different parts of the circuit will show how the current splits:
\(I_{1} = I_{2} + I_{4} = I_{3}\)
This is when:
- current (I) is measured in amps (A)
Potential difference in parallel
Since The capacity for doing work. has to be conserved, the energy transferred around the circuit by the electrons is the same whichever path the electrons follow. Since The potential difference (or voltage) of a supply is a measure of the energy given to the charge carriers in a circuit. Units = volts (V). This is the voltage between two points that makes an electric current flow between them. is used to measure changes in energy, the potential difference supplied is equal to the potential differences across each of the parallel components:
Resistance in parallel
If An electrical component that restricts the flow of electrical charge. Fixed-value resistors do not change their resistance, but with variable resistors it is possible to vary the resistance. are connected in parallel so that the current will flow through either one or the other, but not both, then the overall The opposition in an electrical component to the movement of electrical charge through it. Resistance is measured in ohms. is reduced.