Electrostatic Potential Energy
Two charges and are separated by a distance of 30cm. A third charge initially at point C is shown in figure, is moved along the circular path of radius 40 cm from C to D. If the difference in potential energy due to movement of from C to D is , the value of K is ( = permittivity of free space)

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Answer: (a)
- stays 40 cm from , so only the term changes.
- cm m; cm m.
- So , answer (a).