A rod of length `l` is kept parallel to a long wire carrying constant current `i` . It is moving away from the wire with a velocity `v`. Find the emf induced in the wire when its distance from the long wire is `x`.

Explanation

`E=B//V=(mu_(0)i//v)/(2pix)`
OR
`Emf` is equal to the rate with which magnetic field lines are cut.In `dt` time the area swept by the rod is `/v dt`.The magnetic field lines cut in `dt` time `=B//vdt=(mu_(0)i//vdt)/(2pix)`
`therefore` The rate with which magnetic field lines are cut `=(mu_(0)i//v)/(2pix)`