A mechanic dropped a bolt he needed to repair a car motor. He decided to make a simple electromagnet to try to attract the metal bolt. Which list of material would make the best electromagnet?
a
glass rod for a core, copper wire, 9-volt battery
b
metal rod for a core, copper wire, 9-volt battery
c
plastic rod for a core, copper wire, 9-volt battery
d
wooden rod for a core, copper wire, 9-volt battery
Option b (metal rod for a core, copper wire, 9-volt battery) would make the best electromagnet.
Since the bolt is made of metal, a metal core would be best as it will enhance the magnetic force. Copper wire is a good conductor of electricity and can be coiled around the metal rod to create a magnetic field. A 9-volt battery will provide the necessary electric current to power the electromagnet.
Glass rod (option a), plastic rod (option c), and wooden rod (option d) are not good conductors of electricity and will not enhance the magnetic force.