Question

directions: select each correct answer. more than one answer may be correct.
the electromagnet shown below is made up of a coil of electrical wire wrapped around an iron core.

which of the following would decrease the strength of this electromagnet?

• increasing the number of wire loops in the coil
• increasing the current through the coil
• adding batteries to the circuit
• removing its iron core

Explanation:

The strength of an electromagnet depends on the number of wire loops, the current, and the presence of a magnetic core. Increasing wire loops (A) or current (B, via adding batteries in C) increases strength. Removing the iron core (D) reduces the magnetic field amplification, thus decreasing the electromagnet's strength.

Answer:

D. removing its iron core