Charging a capacitor builds up energy in the electric field between its plates. On a graph of voltage against charge the energy is the area underneath, a triangle, so W = ½QV. The same energy can be written ½CV² or ½Q²/C. Vary C and V and watch the stored energy grow.
MissionPredict what the area under the V-Q graph represents.Streak 0Best 0
The area under a graph of voltage against charge for a capacitor represents:
charge Q = CV600 µC
energy W = ½QV = ½CV²1.8 mJ
The graph of V against Q is a straight line through the origin; the shaded triangle has area ½ × Q × V, which is the stored energy.