GEOLOGY

Detailed explanation-1: -The strength of the magnetic field of an electromagnet increases when: (a) The current (voltage) is increased. The greater the current, the greater the strength. This because the current increases there is more flow of electrons which in turn increases the magnetic field around it.

Detailed explanation-2: -the magnetic field increases when current in the wire of electromagnet increases.

Detailed explanation-3: -There are three ways to strengthen an electromagnet: increasing current. increasing the number of turns of the coil. adding an iron core.

Detailed explanation-4: -The force generated by the aligned atoms creates a magnetic field. A larger piece of iron would have more atoms to align, potentially resulting in a stronger magnetic field than a smaller piece of the same material.