A student makes an electromagnet. He places an iron rod inside a coil of wire and connects the coil to a d.c. power supply as shown below.
The switch is closed so there is a current in the coil. The S pole of a bar magnet is placed near to each end of the iron rod in turn. Suggest what happens at each end of the iron rod and give a reason for your predictions.
Suggestions ................................................................
Reason ...................................................................
