A capacitor stores electric charge and electric potential energy.
Fig. 1.1
Sketch a graph labelling both axes on Fig. 1.1, to show how the charge stored, Q by a capacitor varies with the potential difference, V.
State the feature of the graph in Fig. 1.1 from part (a) that represents the electric potential energy stored by the capacitor.
Calculate the energy stored by a capacitor of capacitance 1200 μF that is charged to a potential difference of 4.5 V.
A healthy debate between two physics students concerns the equations for the energy stored by a capacitor.
A transcript of the debate is given below:
Student A: “The energy stored E by a capacitor is proportional to the potential difference V, because E = QV.”
Student B: “Actually, the energy stored E by a capacitor is proportional to the square of the potential difference, V2, because E =CV2.”
State and explain whether Student A or Student B is correct regarding the energy stored by a capacitor.
The equation for capacitance is: C =
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