Year 13 - Capacitance

Question 1

Polarised Atom/Molecule

Answer 1

An atom/molecule becomes polarised when an external electric field causes the negative electron cloud to be shifted. One end of the atom/molecule becomes positive and the other negative E.g. The molecules of the dielectric in a capacitor.

Question 2

Capacitance

Answer 2

The amount of charge that a capacitor stores for each one volt of pd between the plates, C=Q/V.

Question 3

Capacitor

Answer 3

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

Question 4

Dielectric

Answer 4

An insulating material placed between the two plates of a capacitor. The dielectric increases the amount of charge the plates can store. When the voltage becomes too high electrons jump between the plates through the dielectric. Paper (oiled) is a common dielectric used in capacitors.

Question 5

Time Constant

Answer 5

The time taken for the stored charge to drop to 37%.

Question 6

1 Farad

Answer 6

The capacitor stores 1C of charge for each one volt of pd between the plates