An electric field of `20 N//C` exists along the x-axis in space. Calculate the potential difference `V_B - V_A` where the points A and B are given by
a. `A=(0,0), B=(4m, 2m)`
b. `A=(4m,2m),B=(6m,5m)`

Explanation

(a)
`V_(P) - V_(Q) = Ed = 10 xx 4 = 40` volt
where `d`: distance between two points along electric field
(b) `V_(Q) - V_(P) = -Ed = -10(6 - 4) = -20` volt
(c) `V_(Q) - V_(P) = -Ed = -10(6 - 0) = -60` volt
Note : In the direction of electric field , electric potential decreases.