CIE A Level Physics复习笔记19.1.5 Energy Stored in a Capacitor

• Recall the electric potential energy is the area under a potential-charge graph
• This is equal to the work done in charging the capacitor to a particular potential difference
  • The shape of this area is a right angled triangle
• Therefore the work done, or energy stored in a capacitor is defined by the equation:

• Substituting the charge with the capacitance equation Q = CV, the work done can also be defined as:

• Where:
  • W = work done/energy stored (J)
  • Q = charge on the capacitor (C)
  • V = potential difference (V)
  • C = capacitance (F)

• By substituting the potential V, the work done can also be defined in terms of just the charge and the capacitance:

Step 1: Write down the equation for energy stored in terms of capacitance C and p.d V