Interesting video. The experiment of a compass being placed by a dry cell came up with no current in the wire. When the circuit is completed and terminal (+) has been hooked up with wire placed in such a way that the current in it flows along the old north-south path of the needle. But the needle no longer points north-south. It now points east-west. Switching the wires in the dry cell to opposite terminals, the needle would flip around to the opposite direction but would still point across the wire, not along it.

If the end wire was disconnected and then bent, so it would cross the resting compass needle at 90 degree angle, the circuit was then completed again. This time, the compass needle staying in north-south position.

Telling;
An electric current creates magnetic field
Lines of force run at right angle to the direction of the current