3.7.4 - DEFINITIONS

Question 1

Capacitance, C?

Answer 1

the charge stored per unit pd in a capacitor

Question 2

capacitor?

Answer 2

An electrical component that stores charge. A parallel-plate capacitor is made of two parallel conducting plates with an insulator between them (dielectric)

Question 3

Dielectric?

Answer 3

An insulating material placed between the two plates of a capacitor in order to increase the amount of charge it can store

Question 4

electrical conductor?

Answer 4

a material that contains free electrons that are able to move throughout the material and carry charge

Question 5

electrical insulator?

Answer 5

A material that does not contain any free electrons. All electrons in an insulator are part of the individual atoms that make it up

Question 6

Polarised?

Answer 6

An atom/ molecule becomes polarised when an external electric field causes the negative electron cloud to be shifted in the opposite direction to the positive nucleus - the charges are pulled in opposite directions.

Question 7

Relative permittivity?

Answer 7

the ratio of charge stored in a capacitor with the dielectric to charge stored without the dielectric. Also sometimes referred to as the dielectric constant

Question 8

Time constant?

Answer 8

The time taken for a capacitor to discharge to 37% (e^-1) of its initial charge