Two charges +q and +q are kept at distance of r from each other.If seperation is decreased ,what happens to work done?If one of the charges is replaced by -q and the seperation is decreased what happens to the work done? 

Asked by Rajeev | 22nd May, 2015, 09:03: AM

Expert Answer:

When two charges +q and +q are seperated by a distance r, the electrostatic force of repulsion devloped between them which keep them apart even if the seperation decreased. 
Electric potential due to charge varies inversely as the distance from the charge i.e. begin mathsize 12px style straight V proportional to 1 over straight r end style Therefore, work done also varies inversely as the distance from the charge varies.Hence, as the distance decreased work done also decreased. 
 
When one of charges is replaced by -q  and the seperation is decreased. seperated by distance is called electric diple and electrostatic force of attraction devloped between them.
Electric potential due to charge varies inversely as the distance from the charge i.e. begin mathsize 12px style straight V proportional to 1 over straight r end style
Work done is given as w = Vq. Therefore, work done also varies inversely as the distance from the charge varies. Hence, as the distance decreased work done also decreased. 
 

Answered by Priyanka Kumbhar | 22nd May, 2015, 04:03: PM