{"id":50990,"date":"2025-08-19T14:52:03","date_gmt":"2025-08-19T05:52:03","guid":{"rendered":"https:\/\/phys-edu.net\/wp\/?p=50990"},"modified":"2025-08-19T14:53:06","modified_gmt":"2025-08-19T05:53:06","slug":"the-law-of-electromagnetic-induction-from-power-plants-to-hybrid-cars-unveiling-the-invisible-magic-that-powers-modern-society","status":"publish","type":"post","link":"https:\/\/phys-edu.net\/wp\/?p=50990&lang=en","title":{"rendered":"The Law of Electromagnetic Induction: From “Power Plants” to “Hybrid Cars”! Unveiling the “Invisible Magic” That Powers Modern Society"},"content":{"rendered":"
The term “electromagnetic induction” might sound complicated, doesn’t it? You may have heard of “electromagnetic waves” and “electromagnets,” but “electromagnetic induction” might be a bit of a mystery. However, this phenomenon is an incredibly fascinating principle that is essential to our daily lives. Have you ever wondered as a child, “Wouldn’t it be great if we could generate electricity with the power of a magnet?” The idea of generating electricity just by moving a magnet seems like magic, right? The good news is, that “magic” is actually a reality. And what’s more, the mechanism is the very same one used in the power plants that generate the electricity we use every day. It’s no exaggeration to say that electromagnetic induction is one of the most important technologies humanity has ever acquired. The topic today is this “electromagnetic induction,” which holds the key to power generation. First, let’s conduct a simple experiment to unravel its astonishing principle.<\/p>\n

The Voltage Generated by Electromagnetic Induction<\/h4>\n

Induced Electromotive Force [V] = Number of Turns [N] \u00d7 Change in Magnetic Flux [\u0394\u03a6\/\u0394t]<\/b><\/p>\n

First, let’s start with something familiar. When an electric current flows through a wire, a magnetic field (magnetic flux density) is created around it, right? And when you wrap the wire into a coil, a powerful magnetic field is generated at its center. In short, we can create a magnetic field by passing a current through something.<\/p>\n

Current (movement of charge) \u2192 Creates a magnetic field!<\/b><\/p>\n

This probably reminds you of the electromagnets you learned about in elementary school. But now, doesn’t a question pop into your mind? “Can’t we do the opposite and create a current from a magnetic field?”<\/p>\n

Magnetic field \u2192 Creates a current?<\/b><\/p>\n

If this were possible, we could generate electricity just by moving a magnet. This is exactly what “power generation” is. But can we really do that?<\/p>\n

Let’s find out with an experiment. Take a wire and wrap it around a cylinder (about 3\u20135 cm in diameter) around 50 times to create a coil (a cardboard tube from a roll of plastic wrap works well). Then, connect the coil to a galvanometer (a device that measures the direction and magnitude of a current). The following diagram uses an experimental coil.<\/p>\n

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OK, let’s get ready! Now, gently place a bar magnet in front of this coil. Will a current flow?<\/b>… Unfortunately, the needle of the galvanometer won’t move even a twitch. It seems that a stationary magnet doesn’t produce anything.<\/p>\n

Now, let’s ask a slightly mischievous question. If you were the “God of Electricity,” what would you do to the magnet to make electricity flow through the coil? That’s right\u2014you’d move the magnet!<\/p>\n

Try quickly moving the magnet in and out of the coil’s cylinder. And what happens? The needle of the galvanometer swings widely to the left and right. This shows that a current is flowing. And when you stop moving the magnet, the current immediately stops as well.<\/p>\n

Please also look at this image. When you turn the handle, the magnet rotates. And when the magnet passes near the coil, the light bulb glows for a moment. This was one of the exhibits at the Tsukuba Expo Center.<\/p>\n