Electric circuits + Electrostatics

Polarisation

The separation of charge in a substance in the presence of another charged object

Charge of an electron

1.6 x 10^-19 C

Charge of a proton

1.6 x 10^-19 C

Law of conservation of charge

Charge cannot be created or destroyed, only transferred from one object to another

Coulomb's Law

Two point charges exert force on each other. The force is directly proportional to the product of the charges and inversely proportional to the square of the distance between the charges

Electric fields

A region of space in which an electric charge experiences a force

Current

The rate of the flow of charged particles

Potential difference

The work done per unit positive charge

Resistance

A material's opposition to the flow of electric charge

Emf

The total energy supplied per coulomb of charge by the cell

Power

the rate at which energy is transferred

Resistors connected in series

A potential difference divider

Resistors connected in parallel

A current divider

Factors affecting resistance

Temperature, length, thickness, material

Electric field at a point

the force per unit positive change

conventional current

the flow of positive charge from the positive pole of the cell around the circuit to the negative pole of the cell

Ohm's law

The current through a circuit is directly proportional to the potential difference across the conductor at a constant temperature

1 kWh def.

The energy used by a 1000W appliance operating for one hour

1 kWh conversion to J

1 kWh = 3.6 x10^6J