What are the materials necessary to create an electromagnet? A) power source, metallic core, and electrical conductor

B) metallic core and power source only

C)metallic core magnet, and power source

D)electrical conductor and power source only

A

Explanation:

Electromagnet: It is a temporary magnet. It consists of wrapping coils around iron core and the power source. When the current passes through the coils around the iron core then it will get magnetized. The domains of the electromagnet gets aligned.

As long as the current passes through it, it will get magnetized. It will loose its magnetism easily when the power is switched off.

In the electromagnet, the strength of the magnetism can be increased or decreased. The poles of the electromagnet are not fixed.

layers of the earth affect the waves and these effects are seen on instruiments such as seimometers