7/11/25
Capacitors
Capacitor - 2 electric plates with dielectric between them, potential
difference across them and holds charge.
C = Q/V
Capacitance = charge / potential difference
[Farad] = [CV-1]
Equations for energy based on graph and equation
E = ½ QV
E = ½ CV2
E = Q2/2C
Farad – charge required to increase potential difference by 1V.
Capacitance – ratio of charge on plates of capacitor to potential difference
across them.
Positive plate and negative plate have equal and opposite charge (Q=CV).
Number of electrons = Q/e = charge/charge of electron
Charge of electron = -1.6x10-19 C
10/11/25
Capacitors
, 11/11/25
Discharging capacitors practical
Time constant is how long it takes capacitor to drop to 37% of its
maximum voltage when discharging.
Capacitors
Capacitor - 2 electric plates with dielectric between them, potential
difference across them and holds charge.
C = Q/V
Capacitance = charge / potential difference
[Farad] = [CV-1]
Equations for energy based on graph and equation
E = ½ QV
E = ½ CV2
E = Q2/2C
Farad – charge required to increase potential difference by 1V.
Capacitance – ratio of charge on plates of capacitor to potential difference
across them.
Positive plate and negative plate have equal and opposite charge (Q=CV).
Number of electrons = Q/e = charge/charge of electron
Charge of electron = -1.6x10-19 C
10/11/25
Capacitors
, 11/11/25
Discharging capacitors practical
Time constant is how long it takes capacitor to drop to 37% of its
maximum voltage when discharging.
