Electromagnets work just as well as permanent magnets. In fact, they are even more useful, because you can turn them on and off. You'll find electromagnets in hard drives, speakers and even in sophisticated equipment like MRI machines and CERN's Large Hadron Collider in Geneva, Switzerland. You obviously need a stronger electromagnet for a particle collider than you do for a speaker, so how do scientists make magnets powerful enough to focus a beam of electrons? The answer is a bit more complicated than simply making them bigger, although that's part of it. The materials you use, the voltage you apply and the ambient temperature are all important.
To increase the strength of an electromagnet, you can increase the strength current, and there are several ways to do that. You can also increase the number of windings, lower the ambient temperature or replace your non-magnetic core with a ferro-magnetic material.
It's All About Electromagnetic Induction
Danish scientist Hans Christian Orsted was the first person to notice that a current running through a wire can affect a nearby compass. In other words, it generates a magnetic field. If you wind the wire around a core, forming what is called a solenoid, the ends of the core will assume opposite polarities, just like a permanent magnet. The strength of the field depends on the magnitude of the current, the number of windings and the core material. This is all you need to remember if you want to make the magnet stronger.
Increase Current Magnitude
According to Ampère's Law, the magnetic field around a current-carrying wire is directly proportional to the strength of the current. In other words, increase the current strength and you increase the magnetic field, and there is more than one way to do this: