Capacitors

Question 1

What is a capacitor?

Answer 1

A device used to store electric charge. Consisting of two metal plates separated by some insulating material

Question 2

What is a dielectric?

Answer 2

An insulating material that is places between the two plates of the capacitor

Question 3

What are the types of capacitors?

Answer 3

Electrolytic and Non-Electrolytic

Question 4

Applications of Capacitors

Answer 4

• Tuning radio circuits
• Supercapacitors as car batteries
• Rechargeable batteries
• Smoothing
• Cameras (flash)

Question 5

What is capacitance?

Answer 5

The ratio of the charge on the plates of the capacitor to the potential difference across them

Question 6

What is 1 Farad?

Answer 6

The charge required to increase the potential difference across the plates by 1V

Question 7

What is the S.I. Unit of Capacitance?

Answer 7

1 Farad

Question 8

What does the amount of capacitance a capacitor has depend on?

Answer 8

1. The distance between the plates of the capacitor
2. The area of the plates of the capacitor
3. The insulating material placed in between the plates

Question 9

What does the capacitor do?

Answer 9

1. Reduce the potential difference across the plates
2. Reduce the electric field strength between the plates
3. Increase the capacitance of the capacitor which allows for an increase in the storage of charge

Question 10

Where is the energy of a charged capacitor stored?

Answer 10

In the electric field

Question 11

What is the half life of a RC circuit?

Answer 11

The time taken for the charge or potential difference across it or the discharge current through it to drop to half of any initial value

Question 12

What is the time constant of the capacitor?

Answer 12

The time taken for a capacitor to drop to 1/e or 37% of the supply voltage, charge and current