Factors on which the strength of the magnetic field of an electromagnet depends are:
(i) The number of turns in the solenoid. If the number of turns in the solenoid increases or decreases, the magnetic intensity also increases or decreases.
(ii) It is directly proportional to the strength of the current that flows in the turns of the solenoid.
(iii) It is found to increase further if a soft iron piece, called core, is placed along the axis of the solenoid inside it.
