Question

the electric field inside a parallel plate capacitor is E. find the amount of work done in moving a charge q over a closed r rectangular loop ABCDA.​

Answer 1

Answer:

Due to conservative in nature of electric force, the work done moving a charge in a closed path in a uniform electric field is zero.

Explanation:

Answer 2

answer : workdone by moving charge q over a closed rectangular loop ABCDA is zero.

explanation : see diagram, here ABCDA is a rectangular loop placed in electric field E. as AB = CD = l = length of loop and BC = DA = b = breadth of loop.

then, potential difference across AB, $V_{AB}$ = El

and potential difference across CD, $V_{CD}$ = -El

similarly, potential difference across BC, $V_{BC}$ = 0 [ position vector is perpendicular on electric field lines ]

and potential difference across DA, $V_{DA}$ = 0

now, workdone by moving charge q over a closed rectangular loop ABCDA = q($V_{AB}+V_{BC}+V_{CD}+V_{DA}$)

= q(El + 0 - El + 0)

= 0

hence, workdone by moving point charge q over the closed rectangular loop ABCDA is zero.