Work done is equal to zero because the potential of A and B are the same =4πϵ01aq 
No work done if a particle does not change its potential energy. i.e. initial potential energy = final potential energy.
As per the diagram a point charge +q is placed at the origin O. Work done in taking another point charge - Q from the point A [coordinate (0, a) ] to…
NEET UG 2005 — Physics Electromagnetism
2005mcqhard
As per the diagram a point charge +q is placed at the origin O. Work done in taking another point charge −Q from the point A [coordinate (0,a) ] to another point B [coordinates (a,0) ] along the straight path AB is: 
Official previous-year question
Held on 30 Apr 2005 · Verified 9 Jul 2026.
Options
- A
zero
- B
(4πε0qQa21)⋅2a
- C
(4πε0−qQa21)⋅2a
- D
(4πε0qQa21)⋅2a
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