Lab work. Building the simplest electromagnet and studying how it works
You need insulated wire, an iron nail (the core), a battery (not above 4.5 V), a key and small iron objects (paper clips, nail pieces). Wind the wire onto the nail with a certain number of turns and connect its ends to the battery through the key; do the work only under the teacher’s supervision. Close the key only briefly: the wire and the battery heat quickly. Place small iron objects below the nail and count how many it holds. Then repeat with more turns (or a larger current) and compare the results; try also without the core. Write the results in a table. When finished, first open the key and disconnect the battery. Connecting it to a wall socket is absolutely forbidden; do not touch a hot wire.
Draw a table in your notebook: “number of turns, current (battery), core yes/no, number of clips held”. Fill in sample numbers and write the real results with the teacher.