Capacitance Flashcards
What is capacitance
The charge stored by a capacitor per unit potential difference
How do you work out the energy stored in a capacitor
W=0.5QV
What does a capacitor do?
Capacitors are used to stir charge in a circuit
What two factors determine how much charge can be stored by a capacitor
1) the potential difference across it
2) the capacitance
State the equation used to calculate the capacitance from the charge and potential difference
Capacitance= Charge/Potential difference
C=Q/V
What is the unit of capacitance
CV^-1
Or
F
What is represented by the area under a capacitor’s charge-potential difference graph?
The energy stored by a capacitor
What is represented by the gradient of a capacitor’s charge-potential graph?
Capacitance
Give three equations to calculate the energy stored by a capacitor
W=1/2xQV
W=1/2xCV^2
W=1/2xQ^2/C
what value is given by the product of resistance and capacitance?
The time constant of the circuit
What does the time constant of a circuit tell you
The time the capacitor will take to reach 63% of its total charge, and the time taken for it to discharge to 37% of its full charge
