Two charges `q_(1)` and `q_(2)` are placed `30 cm` apart, as shown in the figure. A third charge `q_(3)` is moved along the arc of a circle of radius `40 cm` from `C` to `D`. The change in the potential energy o fthe system is `(q_(3))/(4pi epsilon_(0))k`., where `k` is

Options

A. `8 q_2`
B. `8 q_1`
C. `6 q_2`
D. `6 q_1`

Answer

A

Explanation

Change in PE `(DeltaU) = U_f -U_i`
`=1/(4piepsilon_0)[(q_1q_3)/(0.4)+(q_2q_3)/(0.1)]-((q_1q_3)/(0.4)+(q_2q_3)/(0.5))]`
`DeltaU=(8q_2q_3)/(4piepsilon_0)=q_3/(4piepsilon_0)(8q_2)`