A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is \(B\). It is then bent into a circular coil of \(n\) turns. The magnetic field at the centre of this coil of \(n\) turns will be:
1. | \(nB\) | 2. | \(n^2B\) |
3. | \(2nB\) | 4. | \(2n^2B\) |