A long straight wire carrying a current `I` and a `II`- shaped conductor with siding connector are located in the same plane as shown in Fig. The connector of length `l` and resistance `R` sides to the right with a current induced in the loop as a function of separation `r` between the connector and the stragiht wire. The resistance of the `II`-shaped conductor and the self-induced of the loop are assumed to be negligible.

Explanation

Field, due to the current carrying wire in the region, right to it, is directed into the plane of the paper and its magnitude is given by,
`B = (mu_(0))/(2pi) (i)/(r)` where `r` is the perpendicular distance from the wire.
As `B` is same length of the rod thus motinal e.m.f
`xi_(i n) = |-int_(1)^(2) (vec(v) xx vec(B)) . d vec(l)| = vB l`
and it is directed in the sense of `(vec(v) xx vec(B))`
So, current (induced) in teh loop,
`i_(i n) = (xi_(i n))/(R) = (1)/(2) (mu_(0) I vi)/(pi R r)`