Introduction to Electric Potential
We must have carried a bag while doing shopping.
To hold that bag , we have to do some work.
Similarly, to hold charge at a point, we need to do work against the electric force.
Letâ€™s understand this more deeply.
Here, a test charge
$+q_{0}$
is placed at a distance
$r$
from a stationary charge
$+q$
.
To hold the charge
$+q_{0}$
at this point, we have to perform some work against the force of repulsion.
This work will be stored in the form of potential energy in the charge.
Thus, the work done in holding a unit charge at a point will be the potential of the field at that point.
It's unit is
$Joule/coulomb$
$(J/C)$
or
$Volts$
$(V)$
.
Now, let's see how this potential varies with the distance between the charges.
Letâ€™s move this test charge from a point A to point B.
Now, if we move the charge
$+q_{0}$
from point A to B, then we have do some work against the force of repulsion.
If
$F_{e}$
is the force of repulsion &
$F$
is the applied force in moving the charge to a small distance
$dr$
, the work done is,
The work done by electric field in moving the charge from point A to B will be,
Since, the displacement is in the opposite direction to that of the applied force therefore,
This work will be stored in the form of electric potential energy in the charge.
And the difference in potential energy of the charge between the point A and B is,
So, the potential difference between the points A and B will be given by,
Revision
The work done in holding a unit charge at a point is equal the potential of the field at that point.
The difference between the potentials at two points in an electric field is termed as the potential difference.
Potential is measured in
$J/C$
or
$Volts(V)$
.
The End