What is a cell?
Supplies electrical energy to a circuit. Longer line shows positive side of cells.
Used for portable devices.
What is a battery?
Has 2 or more cells joined together.
Used for portable devices (+ to -).
What is a lamp?
It lights when current flows through it, converting electrical energy to light energy.
What is a switch?
Allows you to complete or break a
circuit. (Closed switch means current flows).
Used in a light switch.
What is a resistor?
Restricts the flow of current to protect components from too much current.
What is a variable resistor?
Its resistance can be varied.
Used as a dimmer switch to raise or lower the brightness of a lamp.
What is a voltmeter?
Measures potential difference.
Must be placed in parallel to measure the difference in electrical potential between two points.
What is an ammeter?
Measures current. Must be placed in series to measure the current flowing in a circuit.
What is an Ohmmeter?
Ohmmeters measures the resistance in a component in a circuit. No cell required.
What is an LED?
Emits light when a current flows but only allows current to flow in one direction.
Requires less energy than a lamp
Used for car lights.
What is a motor?
Converts electrical energy into kinetic energy by turning.
Used in an electric car.
What is a microphone?
Converts sound energy into an electrical signal.
Used for a microphone at a concert.
What is a loudspeaker?
Converts electrical energy into sound energy.
Used for a loudspeaker at a concert.
What is a photovoltaic cell?
Converts light energy to electrical energy, can be used as the power source in a circuit. More light will mean a greater p.d. across the cell.
Used in a calculator.
What is a fuse?
A fuse is a safety device – the metal core will melt when too much current is flowing in the circuit.
Used for plugs on devices.
What is a diode?
Only allows current to flow in one direction.
What is a capacitor?
Used to store electrical charge, can be used to create a simple timing circuit, or in the flash in a camera.
What is a thermistor?
The resistance of a thermistor will decrease as the temperature increases.
Used in temperature sensors in greenhouses.
What is a LDR?
The resistance decreases as the light increases.
Used for outdoor lighting sensor for light/dark.
What is a relay?
An electronically operated switch. Used to protect operators from high currents, by using a low current supply to switch on a high current/voltage supply.
What is a relay used for?
Safe switching mechanism for high current device.
What is a transistor?
Acts as a switch when a voltage of 0.7 V is applied across the base and emitter.
