Capacitance

• Capacitance:

  $C=$$Q/V$
• Parallel plate capacitors:

  $C=$$ΔQ/ΔV$
• Energy stored in capacitor:

  $=$$QV/2$

  $=$$CV^2/2$

  $=$$Q^2/2C$

  Can also be read as area under garph
• Capacitance in parallel:

  • Vt = V1 = V2
  • Ct = C1 + C2
  • Qt = Q1 + Q2
• Capacitance in series:

  • 1/Ct = 1/C1 + 1/C2
  • Vt = V1 + V2
  • Qt = Q1 = Q2
• Discharge of capacitor:

  $τ=$$RC$

  $X =$$X0 e^-t/RC$