A uniform electric field of magnitude `325 Vm^-1` is directed in the negative y - direction in (fig. 3.12). Theb coordinates of point A are `(-0.2 m , -0.3 m)` and those of point B are `(0.4 m, 0.5 m)`. Calculate the potential difference `V_B - V_A` along the path shown in the figure.
.

Options

A. `+260V`
B. `-260V`
C. `+130V`
D. `-130V`

Answer

C

Explanation

`V_(B)-V_(A)=int_(A)^(C)vec(E).vec(dr)+int_(C)^(B)vec(E).vec(dr)`
`int_(C)^(B)vec(E),vec(dr)=0 rArr V_(B)-V_(A)=-int_(A)^(C)vec(E).vec(dr)`
`=-int_(-0.3)^(0.5)(325)dlcos180^(@)=+325(0.8)=260V`