Question

two uniformly large parallel thin plates having charge densities +sigma ,-sigma are kept in an xz plane at a dis d apart. sketch an equipotential surface due to electric field between the plates. if a particle of mass m as charge q remains stationary between the plates what is the magnitude and direction of the field?​

Answer 1

Answer:

Given two uniformly large parallel plate having charge densities +σ and −σ kept in x-z plane at distance d apart.

We have to sketch an equipotential surface due to electric field between the plates.

Here electric field E between the plates is given by

ε

0

σ

. Now, V=Ed=

ε

0

d

σ

So, any set of equidistant points between the plates will have same electric potential.

We also have electric field between the plates if a particle of mass m and charge −q remains stationary between the plates.

So, the gravitational force experienced by charge =mg

The direction of electric field is downward i.e, along −y axis.

Answer 2

Answer:

The equipotential surface is at a distance d/2 from either plate in X-Z plane.

For a particle of charge (–q) at rest between the plates, then

(i) weight mg acts, vertically downward.

(ii) electric force qE acts vertically upward.

so mg = qE

or E = mg/q, vertically downward.(along – Y-axis)