You can increase the strength of an electromagnet mainly by changing the current, the coil, and the core material.

How Can You Increase the Strength of an Electromagnet?

1. The Core Ideas (Quick Scoop)

The magnetic field of an electromagnet is roughly proportional to two things: the current III and the number of turns NNN of the coil (often written as mmf=NI\text{mmf}=NImmf=NI). So, anything that safely increases current or effective turns, or improves the core material, will boost strength.

2. Practical Ways to Make It Stronger

a) Increase the current in the coil

  • Use a higher-voltage supply or more batteries in series (within the safe rating of wire and power source).
  • Reduce resistance in the circuit: short, thick wire and solid connections allow more current to flow.
  • Use wire with good conductivity (copper is standard; silver is even better but rarely practical).

Safety note: Higher current means more heating of the wire. Always stay within the wire’s current rating and avoid fire or burn hazards.

b) Increase the number of turns of wire

  • Wrap more turns around the core; each loop adds to the total magnetic field.
  • It is fine to add layers of coils; the field inside the core still adds up effectively.
  • Keep coils tight and close together so the field lines reinforce each other efficiently.

This is usually the easiest school‑lab method: more turns of insulated copper wire around the nail or iron rod gives a noticeably stronger pull on paper clips.

c) Use a ferromagnetic core (or a better one)

  • Insert a ferromagnetic core such as soft iron to greatly increase the field compared with air or cardboard.
  • Iron, steel, nickel, and cobalt can all serve as ferromagnetic cores, with soft iron commonly used for strong temporary electromagnets.
  • A non-magnetic core (like aluminium or plastic) will not significantly boost strength.

The core becomes magnetized by the coil’s field, so you effectively get the field of the coil plus the magnetized core together.

d) Improve the circuit and environment

  • Optimize the power supply so it can deliver stable, adequate voltage and current without sagging.
  • Lower the operating temperature (in lab-grade setups) can slightly reduce resistance and help current flow more easily.
  • Keep connections clean and tight so you do not lose voltage across poor contacts.

3. Two- or Three-Point School-Style Answer

If you just need a short, exam-style response:

  • Increase the number of turns of wire in the coil.
  • Increase the current flowing through the coil (for example, by using more batteries in series).
  • Use a soft iron (or other ferromagnetic) core instead of a non-magnetic material.

Any combination of these, done safely, will increase the strength of an electromagnet.

Information gathered from public forums or data available on the internet and portrayed here.