Two long parallel wires carrying current ` 2.5 amperes` and `I ampere` in the same direction ( directed into the plane of the paper) are held at `P and Q` respectively such that they are perpendicular to the plane of paper. The points `P and Q` are located at a distance of ` 5 metres and 2 metres` respectively from a collinear point `R` ( see figure)
(i) An electron moving with a velocity of ` 4xx10^(5) m//s ` along the positive ` x- direction ` experiences a force of magnitude `3.2xx10^(-20) N` at the point `R`. Find the value of `I`.
(ii) Find all the positions at which a third long parallel wire carrying a current of magnitude `2.5 amperes` may be placed so that the magnetic induction at `R` is zero.

Answer

[`+-` 1m form point R aong x-axis]