Question

A U-shaped iron bar is welded onto a flat iron bar, and copper wire is wrapped around each half of the U-shaped bar, as shown.



In order to create an electromagnet, what must be done to this device?

Responses

Both ends of the wire must be attached to each other.
Both ends of the wire must be attached to each other.

An electric current must be applied to the copper wire.
An electric current must be applied to the copper wire.

The entire apparatus must be cooled to just above 0°C.
The entire apparatus must be cooled to just above 0°C.

The number of coils in the wire must be doubled on one side.

Answer 1

An electric current must be applied to the copper wire.