Charge `Q` is given a displacement `vec r = a hat i + b hat j` in an electric field `vec E = E_1 hat i + E_2 hat j`. The work done is.

Options

A. `Q(E_1 a + E_2 b)`
B. `Q sqrt((E_1 a)^2 + (E_2 b)^2)`
C. `Q (E_1 + E_2) sqrt(a^2 + b^2)`
D. `Q sqrt((E_1^2 + E_2^2)^2) sqrt (a^2 + b^2)`

Answer

a

Explanation

`W = vec F . vec r = q vec E . vec r`.