Question

Differentiate between the magnetic field due to a bar magnet and the magnetic field due to a current-carrying solenoid.

Answer 1

Sr. No.	Basis	Bar magnet	Current-carrying solenoid
1.	Source of magnetism	The magnetic field of a bar magnet is produced due to the permanent magnetism of the material.	The magnetic field of a solenoid is produced due to the flow of electric current through the coil.
2.	Nature	The magnetic field of a bar magnet is permanent and cannot be switched off easily.	The magnetic field of a solenoid is temporary and exists only when electric current flows through it.
3.	Control of strength	The strength of the magnetic field of a bar magnet is fixed and cannot be easily changed.	The strength of the magnetic field of a solenoid can be changed by varying the current or the number of turns in the coil.
4.	Magnetic field pattern	The magnetic field lines of a bar magnet emerge from the north pole and enter the south pole outside the magnet.	The magnetic field pattern of a solenoid is similar to that of a bar magnet, with distinct north and south poles at its ends.
5.	Uniformity of field	The magnetic field of a bar magnet is non-uniform.	The magnetic field inside a solenoid is nearly uniform.
6.	Polarity change	The polarity of a bar magnet cannot be changed easily.	The polarity of a solenoid can be reversed by reversing the direction of current.