Q1.
Bring the nail close to the iron paper clips and lift up. Do the clips hang to the ends of the nail?
Answer
Yes. With the coil connected to the cell, the clips cling to the nail and hang from its two ends — you can lift a small chain of them clear of the table.
Why it happens: current in the coil makes a magnetic field; the iron nail sitting inside that field becomes a magnet itself and adds its own magnetism, so the nail now behaves like a bar magnet. The clips are made of iron, a magnetic material, so they are attracted. They gather at the ends because, as in any magnet, the magnetic effect is strongest at the poles.
Safety and care: the book warns you not to keep the wire connected to the cell for more than a few seconds — otherwise the cell weakens quickly, and the wire itself begins to get warm.