Capacitance

Question 1

What is capacitance?

Answer 1

charge stored (Q) per unit potential difference

Question 2

How does a dielectric insulator increase the capacitance of a device?

Answer 2

It polarizes in the electric field

Question 3

What are capacitors used for?

Answer 3

To store and discharge large quantities of energy in a short time period. This makes them useful for short pulses of energy (eg camera flashes).
Important for UPSs.
Used in smoothing to provide a more constant current.

Question 4

How are capacitors used turning AC current into DC current?

Answer 4

The capacitor stores energy as potential difference rises and discharges as potential difference falls.

Question 5

For practical purposes how many time constants will charging/ discharging occur?

Answer 5

5

Question 6

When charging a capacitor which quantities start at max value?

Answer 6

current and potential accross the resistor

Question 7

When charging a capacitor which quantities start at zero?

Answer 7

potential difference of capacitor, charge of capacitor

Question 8

Potentials of the capaicatoe and resistor always add too?

Answer 8

The maximum

Question 9

Why are capacitors used?

Answer 9

Release stored energy very quickly.

Question 10

What are some applications of capacitors?

Answer 10

Huge amounts of power ( energy is released very quickly, capacitor banks)