Capacitor Charge and Discharge Lab for A Level Physics

Watch individual electron-transfer events as a capacitor charges and discharges, then open focused live graphs of charge, potential difference and current.

Learning guide and suggested activities

What this tool shows

  • How electron-transfer events slow during charging and discharging
  • Why electrons move through conductors but not across the dielectric gap
  • How switching to discharge preserves the capacitor charge already stored
  • The 63.2% and 36.8% meanings of one time constant
  • How resistance and capacitance set the RC time scale

OCR A relevance

  • Module 6: Capacitors
  • RC circuits
  • Exponential equations

AQA relevance

  • AQA 7408 section 3.7.4: Capacitance
  • Energy stored by a capacitor
  • Capacitor charge and discharge graphs
  • Time constant RC and time to halve

Try these tasks

  • Set t = RC and compare the charging and discharging percentages.
  • Double R. Explain the changes to RC and initial current.
  • Find the time at which a discharge reaches half its initial charge.
  • Halve capacitor p.d. and compare the new stored energy.