Capacitor Charge Self Test 

1. Two capacitors are in parallel as shown:
(a) Calculate the total capacitance of the combination (2) (b) Work out the total charge held. (2) (c) Calculate the charge held on each capacitor. (3) (d) What do you notice about the two answers you worked out in (c) when compared to your answer to (b)? (1)
2. The two capacitors are now placed in series as shown:
(a) Calculate the total capacitance of this network. (3) (b) Calculate the total charge. What can we say about the charge on each capacitor? (3) (c) Calculate the voltage across each capacitor. (3)
3. A capacitor is discharged using a circuit like this:
(a) What is the product RC called? What are the units? (2) (b) The capacitor has a value of 560 mF and the resistor is 33 k. Calculate the time constant. (2) (c) The start voltage of this discharge is 9.0 V. What is the voltage after RC? (2) (d) What is the voltage after 1 half life? Calculate the time for one half life. (3) (e) Sketch a voltagetime graph to show how the capacitor discharges. What is this kind of graph called? (4) Total = 30 marks

