A student wraps a copper wire around an iron nail. Then she connects the ends of the wire to a battery, making an electromagnet. She notices that if she wraps more coils of wire around the bolt, then her electromagnet can pick up more paper clips. What conclusion can she draw?

Question

More coils of wire increases the density of the copper wire
More coils of wire increases the length of the nail
More coils of wire increases the mass of the battery
More coils of wire increases the strength of the electromagnet

Answer 1

The correct conclusion the student can draw is: More coils of wire increases the strength of the electromagnet.

As she adds more coils of wire around the iron nail, the magnetic field created by the electric current running through the wire becomes stronger. This enhanced magnetic field allows the electromagnet to pick up more paper clips.