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 in the wire when its distance from the long wire is `x`.

Explanation

To find the induced electromotive force (emf) in a rod of length \( l \) that is moving away from a long wire carrying a constant current \( i \), we can follow these steps:

### Step 1: Understand the Setup
We have a long straight wire carrying a constant current \( i \). A rod of length \( l \) is moving away from this wire with a velocity \( v \). At a given moment, the distance of the rod from the wire is \( x \).

### Step 2: Determine the Magnetic Field
The magnetic field \( B \) around a long straight wire carrying current \( i \) at a distance \( x \) is given by the formula:
\[
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