The building procedure of this electromagnet is pretty simple and is done in the following manner:
Clean the iron nail using a piece of dry cloth to set it free from any possible rust or dust layers.
Leaving a certain length of the copper wire free, start winding it over the nail, beginning from the “head" of the nail towards its pointed tip and back, to form alternate layers.
You may stop winding the moment you see a few inches of wire left, so that the winding now has two free wire ends. Bring the two ends together and twist them so that the winding is not able to loosen itself.
Cover the winding with a layer of PVC insulation tape to make the whole assembly more compact and rigid.
With the help of a sharp knife, scrap off to clean the enamel at the free ends of the wire.
Your electromagnet is now ready.
By connecting the cleaned free wire ends to the battery pack (made by inserting two cells in the battery holder) the nail will be instantly turned into a strong electromagnet capable of lifting small iron objects like iron pins, screws, washers, etc.
The electromagnetism effect will instantly vanish as soon as you disconnect the battery supply to it.
Through further modifications and experiments you should be able to study the many other aspects involved with electromagnetism.
Have further doubts regarding how to make an electromagnet? Your valuable comments are most welcome. (Comments need moderation and may take time to appear.)