Answer:
option D is the correct answer of this question.
Particles in solids are tightly packed together.
Instead of moving past each other like liquids and gases, solids tend to vibrate instead
Electromagnet is a type of magnet which is produced by passing electric current through a magnetic material such as iron. Here electric energy is converted to magnetic energy. The magnetic material is coiled with wire through which electric current is passed. Increasing the number of coils and increasing the strength of the current increases the strength of the electromagnet. However, the electromagnet loses its magnetic properties when the current flow is switched off.
(Answer) (1) Increase the number of coils and increase the strength of the current.