Question

Use the figure below to answer the next 5 questions. The distance from A to B "L" and the distance from A to D is also-"L". Calculate the total amount of work WAB done by the electrostatic force on the charged particle "Q" as it moves from A to B. Work from A to B is: Calculate the total amount of work WABC done by the electrostatic force on the charged particle "Q" as it moves from A to B to C. Work from A to B to C is: Now assume that the particle takes a different path to C. Calculate the total amount of work WADC done by the electrostatic force on the charged particle as it moves from A to D to C. Work from A to D to C is: Calculate the work WAGC done by the electrostatic force on the charged particle "Q" as it moves from A straight to C. Work from A to C is: Find the amount of work WABCDA done by the electrostatic force on the charged particle "Q" it moves from A to B to C to D to A. Work from A to B to C to D to A is:

Answer 1

W_{​​​​​​ab} = F.L = QEL

W_{​​​​​​ABC} will be the same as work done in going from A to C because electrostatic force is a conservative force and work done by this force depends on initial and final position and not on path followed.

$W_{ABC}=F[\sqrt{L^{2} + L^2}] cos(45�)$

$W_{ABC}=F\sqrt{2}\,Lcos(45�) = FL= QEL$

W​​​​​_{​​​​​ADC}  = W_{​​​​​​ABC} because initial and final position are same for both paths.

W_{​​​​​AC}  will be same as W_{​​​​​ABC} or W_{​​​​​​ADC} because of same initial and final positions.

W_{​​​​​​ABCDA} will be zero because work done along any closed path in conservative field is zero.

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