Three positive charges lie on the x axis: q1 = 1 × 10−8 c at x1 = 1 cm, q2 = 2 × 10−8 c at x2 = 2 cm, and q3 = 3 × 10−8 c at x3 = 3 cm. the potential energy of this arrangement, relative to the potential energy for infinite separation, is about:
1. 0j2. 0.16j3. 0.079 j4. 0.00085 j5. 0.0017j

Option (4) is the correct answer.

Explanation:

Relation between potential energy and charge is as follows.

                 U =

As it is given that , , and .

        Distance between the charges = 1 cm =  (as 1 cm = 0.01 m)

Hence, putting these given values into the above formula as follows.

                 U =

            =    

            =

            = J

            = 0.00085 J

Thus, we can conclude that the potential energy of this arrangement, relative to the potential energy for infinite separation, is about 0.00085 J.