please solve the question in the picture.

Asked by rohitraman1115 | 13th Jan, 2019, 01:26: PM

Expert Answer:

Work done by external force = q× change in potential 
                                                   =  - q ×kQ×(fraction numerator 1 over denominator x 2 end fraction minus fraction numerator 1 over denominator x 1 end fraction)
                                W= kQq(fraction numerator 1 over denominator x 1 end fraction minus fraction numerator 1 over denominator x 2 end fraction)

Answered by Ankit K | 13th Jan, 2019, 09:09: PM