Components of a circuit, ohms law

Electric Field

The field around charged particles that exerts a non-contact force on other charged particles.

Current

Rate of flow of charge

Non-Contact Force

A force that one object can apply to another object without touching it

Line of Force

The path that a positive charge would follow due to the electric field

Cell

Pushes electrons around a complete cicuit

Battery

Two or more cells

Switch

Enable the current in a circuit to be turned on or off

Lamp

Emits light when current passes through it

Diode

A device that permits current to flow through it in only one direction.

Light-emitting Diode (LED)

combines the propertied of a diode and a lamp

Ammeter

A device used to measure current in a circuit

Fixed Resistor

limits the current in a circuit

Variable Resistor

Allows current to be varied

Fuse

A safety device with a thin metal strip that will melt if too much current passes through a circuit

Heater

Designed to transfer energy from an electric current to heat the surroundings

Voltmeter

A device used to measure voltage, or electrical potential energy difference

Electrons

Negatively charged subatomic particles

Series

A circuit in which all parts are connected end to end to provide a single path of current.

Potential Difference

The work done by each Coulomb of charge

Parallel

A circuit in which parts are connected in separate circuits to each other to provide a single path of current.

Charge Equation

=Energy Transferred÷Potential Difference

Unit of Charge

Coulomb(s)

Unit of Current

Amps

Unit of Potential Difference

Volt(s)

Unit of Resistance

Ohm(s)

equation that links resistance, potential difference and current

resistance = potential difference ÷ current

Ohm's Law

The current through a resistor at a constant temperature is directly proportional to the Potential difference across the resistor

Thermistor

A resistor that changes its resistance with a change of temperature.

Light Dependent Resistor

A resistor which has high resistance in the dark, and low resistance in bright light

Total Resistance of a series circuit

Sum of the resistances of every component

Total potential difference of a series circuit

Sum of the potential differences of every cell

Current of a series circuit

The same current passes through each component

Potential difference in a series circuits

Potential difference is shared between the components

Total Current in a parallel circuit

The sum of the currents through each branch

Total resistance of a parallel circuit

Always less than the resistor with the least resistance

Live Wire

The brown wire in a cable or plug.

Neutral Wire

A wire that carries current away from the component; it is coated in blue plastic.

Three-Pin Plug

connects an appliance to the mains

Short circuit

When the live wire in an appliance touches the neutral wire