Answer:
* Experiment with a higher range of materials
* Use a galvanometer.
* Vary in number of coils of the electromagnet
Explanation:
This is an experiment of electricity and magnetism, in general the best way to improve the results are:
* Experiment with a higher range of materials
allowing to know the scope of the initial assumptions
* Use a galvanometer.
The more accurate the readings the error of the derived quantities is the less which will improve the precision of the experiment.
* Vary in number of coils of the electromagnet
Since it allows to have greater magnetic fields and therefore expand the range of measurements
