MAGNETIC FIELD DUE TO A CURRENT IN A SOLENOID:-
-A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid.
-A current carrying solenoid produces similar pattern of magnetic field as a bar magnet. One end of solenoid behaves as the north pole and another end behaves as the south pole. Magnetic field lines are parallel inside the solenoid; similar to a bar magnet; which shows that magnetic field is same at all points inside the solenoid.
-By producing a strong magnetic field inside the solenoid, magnetic materials can be magnetized. Magnet formed by producing magnetic field inside a solenoid is called electromagnet.