capacitance
What is relative permittivity?
Ratio of charge stored with the dielectric between the plates and the charge stored when dielectric not present
What does the area under thr graph of charge against PD represemt?
The energy stored by the capacitor
What is the time constant?
The time it takes for the charge in a capacitor to fall to 37% of the original value
after how many time condtants is a capacitor considered fully discharged
5
How does a capacitor charge up?
1) Electrons move from negative to positive around the circuit
2) Electrons are deposited on plate A making it negative
3) Electrons travel from B to positive battery giving the plate a positive charge
4) Electrons build on plate A creating a PD across the plates
5) When PD across the plates = spurce PD then capacitor is fully charged
What 2 factors affect the time taken for the capacitor to charge or discharge?
1) The capacitance of the capacitor
2) The resistance of the circuit