Three long, straight and parallel wires carrying currents are arranged as shown in figure. The force experienced by 10 cm length of wire `Q` is

Options

A. `1.4xx10^-4 N` towards the right
B. `1.4xx10^-4 N` towards the left
C. `2.6xx10^-4 N` towards the right
D. `2.6xx10^-4 N` towards the left

Answer

A

Explanation

(a) `F=(4pixx10^-7xx20xx10xx10xx10^-2)/(2pixx2xx10^-2)`
`-(4pixx10^-7xx10xx30xx10xx10^-2)/(2pixx10xx10^-2)`
`=(4pixx10^-7xx10xx10^-2)/(2pixx10^-2)[100-30]`
`=20xx10^-7xx70=1400xx10^-7`
`=1.4xx10^-4N toward right`.