Capacitance

Question 1

What is capacitance

Answer 1

The charge stored by a capacitor per unit potential difference

Question 2

How do you work out the energy stored in a capacitor

Answer 2

W=0.5QV

Question 3

What does a capacitor do?

Answer 3

Capacitors are used to stir charge in a circuit

Question 4

What two factors determine how much charge can be stored by a capacitor

Answer 4

1) the potential difference across it
2) the capacitance

Question 5

State the equation used to calculate the capacitance from the charge and potential difference

Answer 5

Capacitance= Charge/Potential difference
C=Q/V

Question 6

What is the unit of capacitance

Answer 6

CV^-1
Or
F

Question 7

What is represented by the area under a capacitor’s charge-potential difference graph?

Answer 7

The energy stored by a capacitor

Question 8

What is represented by the gradient of a capacitor’s charge-potential graph?

Answer 8

Capacitance

Question 9

Give three equations to calculate the energy stored by a capacitor

Answer 9

W=1/2xQV
W=1/2xCV^2
W=1/2xQ^2/C

Question 10

what value is given by the product of resistance and capacitance?

Answer 10

The time constant of the circuit

Question 11

What does the time constant of a circuit tell you

Answer 11

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