Question

Show that the force on each plate of a parallel plate capacitor has a magnitude equal to (½) QE, where Q is the charge on the capacitor, and E is the magnitude of electric field between the plates. Explain the origin of the factor ½.

Answer 1

Energy on the capacitor = 1/2 QV= Force on each plate × distance of separation
or 1/2 QEd = Force × d
or Force = 1/2 QE

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