Question

A test charge 'q' is mover without acceleration from A to C along the path from A to B and then from B to C in electric field E as shown in the figure.
Calculate the potential difference between A and C.

Answer 1

Since electric field is conservative in nature, the amount of work done will depend upon initial and final positions only.
$\therefore$ Work done $W=\underset{F}{\to }.\underset{d}{\to }=q\underset{E}{\to }.\underset{d}{\to }$

$=qE.4\cos {180}^o$

$=-4_{q}E$
Hence, $V_e-V_A=\frac{W}{q}=-4E$