Topic 5: Electricity and Magnetism Definitions

Drift Speed (v)

the average velocity attained by charged particles in a material due to an electric field.

Electrical Current (I)

the rate of flow of electric charges past a cross-section of a material

Charge q/Q

a scalar property of matter that can cause it to experience a force in an electromagnetic field

Coulomb

the charge carried by an electric current of one ampere in one second

Potential Difference V

is worked done per unit charge also known as voltage

Electronvolt

The amount of energy needed to move an electron through a potential difference of one volt 

Direct Current

a uniform current flowing in one fixed direction in a circuit

Electric Field

is a region of space in which an electric charge “feels” a force

Coloumbs Law

The attractive or repulsive electrostatic force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of their separation

Resistance (R)

is the ratio between potential difference across a component and the current flowing through it

Kirchhoff's First Law

The sum of the currents entering a junction always equals the sum of the currents out of the junction

Kirchhoff’s second law

The net potential difference in a closed loop is equal to zero

Ohms Law

For a conductor at a constant temperature, the current through it is proportional to the potential difference across it

Resistivity (p)

a measure of the resisting power of a specified material against the flow of an electric current

Power (P)

the rate at which energy is transferred

Internal Resistance (r)

the opposition to the flow of current offered by the cells and batteries themselves resulting in the generation of heat

Emf

the work done per unit charge in moving charge from one terminal of the circuit to the other