Capacitance

You will be able to

• Calculate the combined capacitance using 1/C = 1/C₁ + 1/C₂ + … in series and C = C₁ + C₂ + … in parallel.
• Explain why capacitors in series carry the same charge and capacitors in parallel have the same p.d.
• Determine the energy stored from the area under a graph of V against Q, W = ½QV = ½CV².

You will be able to

• Use V = V₀ e^(−t/RC) and the time constant τ = RC to describe the discharge of a capacitor through a resistor.
• Determine the time constant from the gradient of a graph of ln V against t.
• Determine the uncertainty in a gradient from a best-fit line and a worst acceptable line.