Question

The image shows copper wire coiled around an iron nail and connected to a battery to create an electromagnet.

Which factors determine the strength of this electromagnet?



A.
the voltage of the battery and the size of the switch

B.
the number of coils of wire around the nail and the length of the wire in the circuit

C.
the size of the nail and the size of the switch.

D.
the amount of electric current and the number of wire coils around the nail