07. Investigation of the I-V characteristics of a filament of a lamp and a metal wire at constant temperature.

  • 00:31 The ammeter which measures the current and must be connected in series. Why?
  • 00:36 The voltmeter measures the potential difference (p.d.) Why must it be connected in parallel?
  • 00:46 Which is the independent variable and which are the dependent variables?
  • 00:53 What is the:
    -independent variable?
  • What is the dependent variable?
  • Which variable should be plotted on each axis?
  • variable d.c. voltage supply

  • switch

  • ammeter

  • voltmeter

  • component either in the form of a filament bulb e.g. 12 V, 24 W bulb or a metal wire e.g. 1 m length of constantan mounted on a wooden batten

Hazard Risk Control measure


Heat – wires can get hot.

Students should wear eye protection and should only connect the power when taking measurements.