. Explain the Magnetic field due to Solenoid
A solenoid is a long cylindrical helix which is obtained by winding closely a large number of turns of insulated copper wire over a tube of card board or china clay. When electric current is passed through it, a magnetic field is produced around and within the solenoid. If n be the number of turns per unit length of the solenoid, then number of turns in width dx = ndx.
If ‘i’ current is passing through it then magnitude of magnetic induction at P.