Two square plates of side are separated by and maintained at a constant by an ideal…

PHYSICS · Subjective · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance

Problem

Two square plates of side

5.0\,\text{cm}

are separated by

1.0\,\text{mm}

and maintained at a constant

1000\,\text{V}

by an ideal power supply. A dielectric slab of thickness

1.0\,\text{mm}

and dielectric constant

\kappa=6

is pushed horizontally into the space between the plates from one edge. At a given moment the slab overlaps a length

x

of the plates, so the overlap area is

x\,(5.0\,\text{cm})

. (a) Derive an expression for the magnitude of the horizontal force on the slab as a function of

x

(neglect edge effects). (b) Evaluate the force when

x=2.5\,\text{cm}