• 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.