A student built a simple electromagnet with copper wire, an iron bolt, and a 1.5-volt battery. The electromagnet was able to lift a paper clip from 3 centimeters away. Select THREE ways the student can increase the strength of his electromagnet.
A. He can use a thicker piece of copper wire.
B. He can reverse the orientation of the battery.
C. He can replace the iron bolt with a wooden rod.
D. He can add a switch between the battery and the iron bolt.
E. He can replace the 1.5-volt battery with a battery of higher voltage.
F. He can use a longer piece of wire that wraps more times around the bolt.