The battery clips did not have a mark on which one is positive and which is negative. Can you find out with only a compass and a coil of wire at your disposal?
You can find out if there is current in the conductor without using an ammeter by the behavior of the magnetic needle near the conductor. The current always has a magnetic effect, so if the arrow deflects, then there is current.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.