michael faraday | law of electromagnetic induction | faraday's law of induction

Summary

In this video, we explore Faraday's law of electromagnetic induction, a fundamental discovery by Michael Faraday in 1831. The video explains how a current is induced in a coil when a magnet is moved towards or away from it, demonstrating the concept of changing magnetic flux. Through experiments, we learn that the induced current depends on the rate of flux change, not the magnet's motion itself. The video also covers Faraday’s first and second laws, which explain how electromotive force (EMF) is generated. These principles are key to understanding how electricity is produced through magnetic fields.

Takeaways

• 😀 Faraday's Law of Electromagnetic Induction explains how a changing magnetic field induces an electric current in a conductor.
• 😀 Michael Faraday and Joseph Henry independently discovered the phenomenon of electromagnetic induction in the 1830s, with Faraday publishing first.
• 😀 The experiment involves a coil connected to a galvanometer, and a bar magnet whose movement induces a current in the coil.
• 😀 The galvanometer needle deflects when the magnet moves toward or away from the coil, showing the presence of an induced current.
• 😀 No current is induced when the magnet is stationary, proving that the movement of the magnet is necessary for induction.
• 😀 The key factor in induction is the change in magnetic flux (the number of magnetic field lines passing through the coil), not just the motion of the magnet.
• 😀 Faraday’s First Law of Induction states that the induced electromotive force (EMF) in a conductor is proportional to the rate of change of magnetic flux.
• 😀 The experiment demonstrates that the induced current is directly related to the change in the magnetic field linked to the coil.
• 😀 Faraday’s Second Law of Induction further explains that the magnitude of the induced EMF depends on the rate at which the magnetic flux changes.
• 😀 The video clarifies that induced current occurs due to a change in magnetic flux, not because of the magnet’s motion alone, leading to a clearer understanding of electromagnetic induction.

Q & A

What is Faraday's Law of Electromagnetic Induction?

Faraday's Law of Electromagnetic Induction states that a change in magnetic flux through a conductor induces an electromotive force (EMF) in the conductor. This principle is fundamental to understanding how electric currents can be generated through the movement of magnetic fields.

Who first discovered electromagnetic induction and when?

Electromagnetic induction was independently discovered by Michael Faraday in 1831 and Joseph Henry in 1832. Faraday was the first to publish his experimental results.

What is the role of the galvanometer in Faraday’s experiment?

The galvanometer is used to detect the induced electric current in the coil. It shows the deflection of the needle when an electric current is present, indicating that electromagnetic induction has occurred.

What happens when the bar magnet is moved towards the coil?

When the bar magnet is moved towards the coil, the magnetic flux linked to the coil increases, inducing an electric current. This is indicated by a deflection in the galvanometer needle.

Why does the galvanometer needle stop moving when the magnet stops moving?

The galvanometer needle stops moving when the magnet stops moving because the change in magnetic flux ceases. Current is only induced when there is a change in magnetic flux, either by moving the magnet closer or farther away from the coil.

What occurs when the magnet is moved away from the coil?

When the magnet is moved away from the coil, the magnetic flux linked to the coil decreases, inducing an electric current in the opposite direction, as indicated by the opposite deflection of the galvanometer needle.

How does the rate of motion of the magnet affect the induced current?

The faster the magnet moves, the greater the rate of change in magnetic flux, which results in a larger induced electromotive force (EMF) and a higher current in the coil.

What is meant by 'magnetic flux' in the context of this experiment?

Magnetic flux refers to the total number of magnetic field lines passing through a given area, such as the cross-sectional area of the coil. Changes in magnetic flux, caused by the movement of the magnet, induce an electric current in the coil.

What is Faraday’s Second Law of Induction?

Faraday's Second Law of Induction states that the magnitude of the induced electromotive force (EMF) is directly proportional to the rate of change of magnetic flux through a conductor. The faster the flux changes, the higher the induced EMF.

How does the experiment with two coils help explain electromagnetic induction?

In the experiment with two coils, the change in magnetic flux in the first coil induces a current in the second coil, even though there is no motion of a magnet. This demonstrates that a change in magnetic flux can induce a current in a conductor, regardless of whether motion is involved.