Answer:
He should add another battery.
Step-by-step explanation:
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a core of magnetic material usually an iron core. When an electric current-producing battery is connected to the wire, an electric current will begin to flow and the iron core will become magnetized. When the battery is disconnected, the iron core will lose its magnetism.
Electromagnets works based on the electromagnetic field which is a field force due to the interaction of the electric and magnetic fields. the force on the wire is proportional to the size of the current, the length and thickness of the iron core, as well as the number of turns of wire around the iron core.
Therefore, from the number of possible action given that the student can take in order to increase the magnetism of his electromagnet, adding another battery, thereby increasing the current will be the best way to increase the number of paper clips tat his electromagnet can pick up.