Magnetic Field Definition A magnetic field is a field of force that is created either by: Moving electric charge Permanent magnets Permanent magnets are materials that produce a magnetic field A st...
The Time Constant The time constant of a capacitor discharging through a resistor is a measure of how long it takes for the capacitor to discharge The definition of the time constant is: The time t...
Capacitor Discharge Graphs So far, only capacitors charged by a battery have been considered This is when the electrons flow from the positive to negative plate At the start, when the capacitor is ...
Calculating Energy Stored in a Capacitor Recall the electric potential energy is the area under a potential-charge graph This is equal to the work done in charging the capacitor to a particular pot...
Area Under a Potential–Charge Graph When charging a capacitor, the power supply pushes electrons from the positive to the negative plate It therefore does work on the electrons, which increase thei...
Capacitors in Series & Parallel Recall the formula for the combined capacitance of capacitors in series: In parallel: Ctotal = C1 + C2 + C3 ... Worked Example Three capacitors with capacitance ...
Derivation of C = Q/V The circuit symbol for a parallel plate capacitor is two parallel lines Circuit symbol for a capacitor Capacitors can be combined in series and parallel circuits The combined ...
Defining Capacitance Capacitors are electrical devices used to store energy in electronic circuits, commonly for a backup release of energy if the power fails They can be in the form of: An isolate...
Electric Potential Energy of Two Point Charges The electric potential energy Ep at point in an electric field is defined as: The work done in bringing a charge from infinity to that point The elect...
