Question

When an iron rod is placed inside a current-carrying coil of wire _________.

Answer 1

Step-by-step explanation:

The magnetic field due to a current carrying coil is given by

`B = \mu _(0)ni`

Where, μ0 is the permeability of free space, n be the number of turns per unit length and i be the current.

When an iron rod is placed inside, the magnetic field incraeses, because the magnetic field is given by

`B' = \mu _(0)\mu _(r)ni`

Where, μr is the relative permeability of iron, which is more than 1. So, the magnetic field increases.