Imagine you are holding a simple coiled copper wire. 

Now again imagine an electric current flowing through it, like water rushing through a pipe that you garden has. But instead of creating a splash, this flow of electrons does something extraordinary—it generates a magnetic field. It’s invisible, yet it influences everything around it, including your plants.

How does this happen? Why does a moving current create a magnetic field? Let’s break it down with diagrams and a quick look into the fascinating world of electromagnetism. 

Fun Fact: If somehow we can advance the Electromagnetism Theories, we might be able to create flying saucers, yeah, we will be able to make UFOs.

Electricity and Magnetism as Two Sides of the Same Coin

Electricity and magnetism are deeply intertwined. And in this section, we will revisit the thing you must have learnt in high shools. Let's move on it.

Electricity and Magnetism are like dance partners, in the hall of physics, moving in harmony according to mathematical equations, which describe the interactions between electric and magnetic fields. So, what's the matter here?

When current flows through a wire, it doesn’t just move electrons—it creates a magnetic field around the wire. This isn’t just a quirky effect; it’s a fundamental aspect of how the universe operates. But why? Let's answer this in the next section.

Figure 1: A straight current-carrying wire creates a circular magnetic field around it.

Why Does a Coil Generate a Magnetic Field?

To understand why a coil generates a magnetic field, we need to visualize what’s happening with the charges in the wire. These charges, when in motion, disturb the space around them, creating a magnetic field as a natural consequence.

But here’s where it gets interesting: "The presence and strength of this magnetic field depend on your perspective. If you’re stationary while the current flows, you observe a magnetic field around the wire. However, if you were moving alongside the flowing electrons, you might see only an electric field, not a magnetic one."

This phenomenon is rooted in special relativity, which tells us that electric and magnetic fields are two aspects of the same thing—the electromagnetic field. The magnetic field, in a sense, is how we perceive the electric field when viewed from a different reference frame.

Optimizing the Magnetic Field: The Power of a Coil

A straight wire creates a magnetic field, but when you wind the wire into a coil (known as a solenoid), the magnetic fields from each loop combine. This combination strengthens the magnetic field inside the coil. 

It really is, what it is  :X

Figure 2: The magnetic field lines inside a coil are strong and uniform, while outside the coil, they spread out and weaken.

Inside the coil, the magnetic field lines are nearly parallel and close together, indicating a strong, uniform field. This uniformity, this alignment, this arrangement is why coils are used in electromagnets, transformers, that you use! Understand?

A Simple Tool to Determine Field Direction

The right-hand rule is a handy way to determine the direction of the magnetic field generated by a current-carrying coil. If you curl the fingers of your right hand in the direction of the current through the loops, your thumb points in the direction of the magnetic field inside the coil.

Right hand rule is not real, it's just a conventional rule, in reality the Left Hand Rule is Happening, jokes apart, There is a Left Hand Rule too, learn about it too :)

Figure 3: Using the right-hand rule to determine the direction of the magnetic field inside a coil.

Conclusion

The magnetic field generated by a coil is more than just a curiosity of my mind—it’s a demonstration of the deep connection between electricity and magnetism. This regulates the shapes the world around us, influencing everything from how our devices work to how the Earth itself functions.

Next time you see a coil, whether in a gadget or a large machine, remember the invisible dance of electric charges and magnetic fields. It’s a dance that’s happening all around us, quietly powering our modern world.

They Dance. Riyal.

Thank you for reading :)