Which of the following is an example of an electromagnet? A. The magnets used to lift metal or cars in a salvage/junk yard
B. the bar magnets we used in the lab
C. the magnets used to hold pictures on a refrigerator or papers on a metal filing cabinet

A. The magnets used to lift metal or cars in a salvage/junk yard

Explanation:

An electromagnet  is defined as a type of magnet which are made up of wires in coil shape. Magnetic field in these wires are produced by electric current.

An example of an electromagnet is magnets used to lift metal or cars in a salvage/junk yard because a crane is used in junkyard to lift metal in which crane is attached to a iron disc and when electricity is off, the disc move downwards and placed near required metal and switch on the electricity when disc reaches on metal or cars to be lifted. This electricity generates magnetism in the iron disc and attract metal or cars from the junkyard.

Hence, the correct answer is "A. The magnets used to lift metal or cars in a salvage/junk yard".