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19. Capacitance

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  1. 19.1 Capacitors and capacitance

    1. • define capacitance, as applied to both isolated spherical conductors and to parallel plate capacitors

    2. • recall and use C = Q / V

    3. • derive, using C = Q / V, formulas for the combined capacitance of capacitors in series and in parallel

    4. • use the capacitance formulas for capacitors in series and in parallel

  2. 19.2 Energy stored in a capacitor

    1. • determine the electric potential energy stored in a capacitor from the area under the potential–charge graph

    2. • recall and use W = 1/2 QV = 1/2 CV 2

  3. 19.3 Discharging a capacitor

    1. 19.3.1The variation with time of potential difference, charge and current

      • analyse graphs of the variation with time of potential difference, charge and current for a capacitor discharging through a resistor

    2. 19.3.2Τ = RC for the time constant for a capacitor discharging through a resistor

      • recall and use τ = RC for the time constant for a capacitor discharging through a resistor

    3. 19.3.3Equations of the form x = x0 e–(t / RC) where x could represent current

      • use equations of the form x = x0 e–(t / RC) where x could represent current, charge or potential difference for a capacitor discharging through a resistor