00:01
Hi, here in this given problem first of all there is a charge, positive charge 2 .0 nano coulomb, then around this charge there are equipotential surfaces, the first one and the second one.
00:25
Over the first equipotential surface there are two points, point a, point b, its radius is given as 1 .0 cm and over the second surface the point is c and its radius is given as 2 .0 cm.
00:55
The charge is given as 2 .0 nano coulomb or we can say this is 2 .0 multiplied by 10 to the power minus 9 coulomb.
01:05
In the first part of the problem we have to find potentials at point a and b and c and as a and b are at equipotential surface, so v a will be equal to v b, potential will be same that will be given by the expression k into q by r, k 9 into 10 to the power 9 q, 2 into 10 to the power minus 9 coulomb divided by r 1 cm or 1 into 10 to the power minus 2 m.
01:51
So this potential at a and b that is calculated to be equal to 1800 volt.
02:00
First two answers for the first part of the problem.
02:04
Then we have to find potential at c, v c using the same expression k q by r, 9 multiplied by 10 to the power 9 q that is 2 into 10 to the power minus 9 divided by r that is 2 cm or 2 into 10 to the power minus 2 m.
02:23
And finally this potential at c comes out to be equal to 900 volt.
02:30
Third answer for the first part of the problem.
02:35
Then in the second part of the problem we have to find electrostatic potential energy of the charge put at the points a, b and c.
02:47
And we know electrostatic potential energy of the charge u, this is given as the product of that charge with the potential at that point.
03:01
So u a that will be given by as this is the potential energy of electron, so for electron that is minus 1 .6 multiplied by 10 to the power minus 19 coulomb multiplied by v which is 1800 volt...