NEET-XII-Physics
31: Capacitors
- #7When a dielectric slab is gradually inserted between the plates of an isolated parallel-plate capacitor, the energy of the system decreases. What can you conclude about the force on the slab exerted by the electric field?Ans : As the energy of the system decreases, the change in the energy is negative.
Force is defined as a negative rate of change of energy with respect to distance.
F = `` -\frac{\partial U}{\partial x}``
So, as the energy decreases, the force due to the electric field of the capacitor increases when the dielectric is dragged into the capacitor.
Page No 164: