Capacitors 3

1. Describe the structure of a capacitor.
two metal plates separated by a short gap

2. What does a capacitor do?
stores charge, and releases charge rapidly

3. Define capacitance.
Capacitance is a measure of the ability of a capacitor to store charge.

4. What exactly is Q?
A. Q is the sum of the charges of both plates
B. Q is the magnitude of charge stored on either plate
C. Q is the average charge stored on both plates
D. Q is the difference in charge stored between the plates
B

5. What is the total charge on the plates?
zero

6. Explain how a capacitor can be used to provide a large potential difference for a very short time.
The release of charge is a simple discharge process from a conductor. Hence by connecting a capacitor into a circuit, in the same way a battery would be connected, a large amount of charge is instantly released. The charge release is NOT controlled by a chemical process.

7. When required, charge from one plate reaches the other by travelling:
A. through the dielectric
B. via an external conductor
B

8. Why is the farad usually expressed in microfarads (F), nanofarads (nF), or picofarads (pF)?
The farad is typically a very small unit.

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