DC Circuits and Capacitors

Students find the circuit rules can be difficult to get the hang of. It is a good idea to keep revisiting Kirchoff's Laws as you teach each aspect of the circuit:

  • conservation of charge and energy in circuits
  • relationships between currents, voltages and resistances in series and parallel circuits
  • power dissipated

The idea of ratio in a potential divider circuit can throw some students. There are a number of different ways to calculate the effect of a potential divider circuit. However if students don't have a good grasp of the mathematical relationship they will struggle. It is a good idea to introduce potential dividers, then go back to teach internal resistance, then revisit potential dividers when the students are more confident:

  • potential divider circuits

Capacitance is a good topic to introduce exponential decay as the decay curves are easily produced using data logging software:

  • definition of capacitance
  • energy of a capacitor
  • quantitative treatment of charge and discharge curves

Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS or recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance.