Answer:
C.) A power source (like a battery)
Step-by-step explanation:
To create a simple electromagnet, you would need three things:
A solenoid: This is a coil of wire that serves as the winding of the electromagnet. When an electric current flows through the wire, it generates a magnetic field.
An iron core: This can be a piece of iron or a ferromagnetic material, such as a nail, that is placed inside the solenoid. The iron core helps to concentrate and strengthen the magnetic field generated by the solenoid.
A power source: This is needed to supply electric current to the solenoid and create the magnetic field. Typically, a battery is used as the power source for a simple electromagnet. The battery provides the necessary voltage and current to energize the solenoid and create the magnetic field.
The other options (A, B, and D) are not required to create a simple electromagnet. A resistor is not necessary as it is used to limit current flow in a circuit. A generator is used to produce electricity from mechanical energy and is not needed for a basic electromagnet. A switch is used to control the flow of electricity but is not essential for the basic functioning of an electromagnet.