Static Electricity

Question 1

Static charge

Answer 1

An electric charge that cannot move. Often found on electrical insulators where charge cannot flow freely. Static charge can build on a conductor if isolated.
Rubbing 2 insulators together (electrons cannot move through them) -> electrons transferred from one to the other (by friction) - 1 material gains electrons, negatively charged, other loses electrons, positively charged of equal amount.

Question 2

Electrical insulators

Answer 2

Electrical charges cannot easily move through electrical insulators.

Plastic & rubber are good insulators

Question 3

Electrical conductors

Answer 3

Electrical charges can easily move through electrical conductors.

Metals are good conductors

Question 4

Sparks

Answer 4

Too much electric charge builds up on object (p.d between object & earth increases).
Charged object has strong electric field -> electrons in air particles removed by ionisation
Electrons can jump through more conductive air (high p.d), between charged object & earth (or earthed object) - creates spark

Question 5

Earthing

Answer 5

Providing an easy route for excess charge to flow into the ground - prevents charge from building up

Question 6

Electric fields

Answer 6

Charged objects create an electric field around themselves (strongest closer to object)
Another charged object placed in field experiences a force (stronger as objects get closer)
Like charges repel, opposite charges attract (electrostatic attraction/repulsion - non-contact force)