A dielectric slab is introduced between the plates of an isolated capacitor. The force acting between the plates will

Step-by-step solution

For an isolated capacitor, the charge Q on the plates remains constant. The force between the plates of a capacitor can be calculated using the relation F = - dU dx , where U is the electrostatic potential energy stored in the capacitor and x is the separation between the plates. When a dielectric slab of thickness t and dielectric constant K is introduced between the plates, the capacitance becomes: C = ₀ A x - t + t K The energy stored in the capacitor is: U = Q^2 2C = Q^2 2 ₀ A ( x - t + t K ) Differentiating U