Joey and McKaleb build an electromagnet by wrapping a wire around a nail and connecting the wire to both terminals of a battery. When they connect the battery, they discover that the electromagnet can pick up 5 paperclips. They want to be able to pick up 8 paperclips. Joey and McKaleb brainstorm and think of 4 ways to modify their experiment so the electromagnet will pick up 8 paperclips. Which of these do you think they should try?

A) All of these will increase the strength of the magnet since the strength of the magnet can be increased by changing the wire loops or the battery.

B) Number 1 and 2 will increase the magnetic force, but number 3 and 4 will not increase the strength of the magnet.

C) Number 1, 2 and 4 will increase the strength of the magnet, reversing the battery will make the magnet repel the paperclips.

D) None of these will work. The boys should add a real magnet in addition to the electromagnet if they want to pick up more paperclips.