Unit 4 Electricity and magnetism

Notes
  • Current is measured using an ammeter.
  • An ammeter has very low resistance to current and so does not affect the current in the circuit: it simply measures it. An analogue ammeter gives a reading with a needle moving across a scale; a digital ammeter has a numerical reading displayed.
  • The analogue ammeter below shows a current of 0.50A.

    analogue ammeter

  • The digital ammeter below shows a current of 1.26A.

    digital ammeter

  • An ammeter is always placed in series with other components in a circuit.

    series circuit

 
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