The influence of physics on the magnetic size of electromagnet is:
One is related to the number of turns of the coil, and the number of turns can be changed by wiring method.
Two. In relation to the current size of the conductor, the current through the conductor can be changed by the sliding rheostat, and the current can be increased by increasing the number of batteries.
Three, with or without iron core, iron core has strong magnetism, and iron core has no magnetism.
Four. It is related to the permeability of soft magnetic material of conductor.
Five. It is related to the cross section of the iron core.
What we learn is mainly related to the first three parts.
In our daily life, we can also make electromagnets and carry out experiments. The tools we need are conductors, iron nails, batteries and so on. The control variable method can help us to make a change, and other kinds of non change, for example, when the study is related to the number of turns, two electromagnets can be connected in a circuit. Ensure that the current and core will not change.