Question

Assertion (A) : The work done by the electrostatic force is zero when a point charge moves in a circular path around another charge.
Reason (R) : The dot product of force and displacement vectors gives work done.

• A. Both (A) and (R) are collect and (R) is the correct explanation of (A)
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• C. (A) is correct but (R) is not correct
• D. (A) is not correct but (R) is correct

Answer 1

Answer: (A)

$\because$ Work done, $W= F \cdot s =F s \cos \theta$
work done is zero when force acts at right angle to the direction of motion of charges hence, $W=F s \cos 90^{\circ}=0 .$ The work done by the electrostatic force is zero when a point charge moves in a circular path around another charge.
Since, the electrostatic force acts at right angle to the direction of motion of the charges.