Physics for IGCSE & O level - Magnets And Currents (Section 5 - No. 31)
What will increase the strength of the magnetic field of an electromagnet?
Increasing the current
Increasing the number of turns in the coil
Reversing the current direction
Using an iron core
Forklaring
Increasing current, more coil turns, and the use of a ferromagnetic core such as iron will increase field strength.