1. <em>The student could increase the number of loops of wire around the iron core. </em>Increasing the number of windings will increase the strength of the electromagnet also known as the magnetomotive force.
2. <em>The student could use a bigger battery so that the voltage is increased. </em>Thus, according to Ampere's Law, the magnetic field around the current-carrying wire will also increase as it is directly proportional to the current's strength.