Leaving Cert Physics: Electricity Definitions

Potential difference

The work done in moving a unit positive charge from one point to the other

Volt

The potential difference between two points is 1 volt if the work done in moving a charge of 1 coulomb from one point to the other is 1 joule

Capacitance

The ratio of the charge on the body to its potential

Farad

A body has a capacitance of 1 farad if the addition to the body of 1 coulomb raises the potential

Ohm's Law

States that for a metallic conductor at constant temperature the current will be proportional to the voltage

Resistance

The ratio of the voltage across an electrical circuit to the current flowing through it

Conductor

A material that tends to allow a flow of electrons

Insulator

A material that tends to restrict a flow of electrons

Coulombs Law

States that the force between two point charges is directly proportional to the product of the charges, and inversely proportional to the square of the distance between them

Electric field strength

The force per unit positive charge at a point in an electric field

Ohm

A conductor has a resistance of 1 ohm if a current of 1 amp flows when a voltage of 1 volt is applied

Resistivity

The resistance of an object of material with unit area and unit length

Joules law

The rate at which heat is produced by an electric current is proportional to the square of the current

Semiconductor

A material whose resistivity lies between that of a conductor and an insulator

Magnetic flux density

The force experienced by a conductor of length 1 m carrying a current of 1 A at right angles to the field.

Ampere

That current which, if maintained in two parallel, infinitely long wires of negligible cross-section placed one metre apart in a vacuum, would produce between the wires force of 2x10-7 newtons per metre length of the wire

Faraday's Laws

These laws state that when there is a change in the magnetic flux linking a coil, an emf is induced in that coil. The strength of the emf is proportional to the rate of change of the flux linking the coil

Lenz's law

States that the direction of an induced current is such as to oppose the change causing it

Still learning (6)

You've begun learning these terms. Keep up the good work!