A student wraps 10 coils of copper wire around an iron bolt, and then she connects the ends of the wire to a battery. Next, the student uses the nail to lift paper clips. She then conducts a second trial using the same wire, battery, and nail, but with 30 coils of copper wire wrapped around the bolt. What will happen in the second trial?

Question

A. The bolt will lift the same number of paper clips, because both trials used the same type of battery.

B. The bolt will lift the same number of paper clips, because both trials used the same type of paper clips.

C. The bolt will lift less paper clips, because more conductive material in the system will balance more paper clips.

D. The bolt will lift more paper clips, because more coils of wire produces a stronger magnetic field.

Answer 1

The correct answer is:

D. The bolt will lift more paper clips, because more coils of wire produces a stronger magnetic field.

In an electromagnet, the strength of the magnetic field generated is proportional to the number of coils of wire wrapped around the core (in this case, the iron bolt). By increasing the number of coils from 10 to 30, the strength of the magnetic field increases, which allows the electromagnet to lift more paper clips.