Electricity

• Current is a flow of electrical charge in a circuit.

• There are two types of current: direct and alternating.

• The unit of electric current is ampere.

• Electric charge is measured in coulombs (C).

• Direct current is the flow of electric charge in one direction.

• Alternating current is when the electrons flow continually reverse.

• An ammeter is used to measure the current in a circuit.

• A voltmeter is generally used for measuring electrical potential difference between two points in an electric circuit.

• LDR is short for light dependant resistor.

• In a bright light, the LDR's resistance goes down.

• In darkness, the LDR's resistance goes up.

• LDR can be used in a circuit to automatic night lights, burglar detectors.

• An LDR is a resistor that is dependant on the intensity of light.

• The resistance of a thermistor is highly dependent on its temperature.