P4 Flashcards
What is an circuit diagram ?
A circuit diagram shows how the components on a circuit are connected together .
What is a cell ?
A cell is necessary to push electrons around a complete circuit .
What is a battery ?
A battery consists of two or more cells .
What is a switch ?
A switch enables the current in a circuit to be switched on or off .
What is an indicator ?
An indicator , such as a bulb is designed to emit light as a signal when a current passes through it .
What is a diode ?
A diode allows current through in one direction
What is an LED ( light emitting diode )
An LED emits light when a current passes through it
What is an ammeter ?
Used to measure an electric current
What is a fixed resistor ?
Limits the current in a circuit .
What is a variable resistor ?
Allows the current to be varied.
What is a fuse ?
A fuse is designed to melt and therefore break the circuit if the current passing through it , is greater than a certain amount .
What is a heater ?
Designed to transfer the energy from an electric current to heat the surroundings .
What is a voltmeter ?
Used to measure potential difference .
What is an electric current ?
The flow of electrons around a circuit
What are three sources of potential difference ?
A cell , a battery and an electrical generator .
In which direction do the electrons travel ?
Clockwise
What is potential difference also known as ?
Voltage
Where can you place a voltmeter ?
Across a cell / battery or across a lamp .
What is electric charge measured in ?
Coulombs
What is electric current measured in ?
Amperes
What is the equation for charge flow ?
Current x time taken
What is Resistance ?
When vibrating atoms in a component prevent the passage of electrons through the torch bulb
