Experiments of Faraday and Henry: Overview, Questions, Preparation

After years of extensive hardwork, Michael Faraday and Joseph Henry finally found the technique through which motion and magnetism could be used to generate electricity. These foundations helped modernize the technologies and introduced various new changes in the field of science. Here’s how:

Electromagnetic Induction:

Earlier, electricity and magnetic properties were seen as separate fields. Their combination created a new source that contributed to the field of electromagnetism.

Maxwell’s Equations:

These discoveries laid the base for Maxwell to help develop new innovative formulas, which gave a new definition to electromagnetism.

Modern Appliances:

Devices such as radio, mobile, TV, solar panels, Bluetooth/wifi, etc. could be designed using these principles of electromagnetism, which improvised the technologies.

Electrical Energy:

Before, people only saw chemical and mechanical energies as the source of their work. Electricity could be used for producing energy only because of these discoveries in the later times.

The Faradays Coil and magnetic trick was an experiment conducted with the aim of demonstrating the principle of electromagnetic induction, which states that a change in the magnetic field could be successfully used to generate electric current.

To prove this theory, faraday used a coil of wire connected to a galvanometer along with a magnet. Now, he observed that when the magnet is moved into the coil, the galvanometer needle detected the flow of electric current. Then, he pulled out the magnet from the coil and noticed that the needle comes back to its original position, which indicates that the flow of current has stopped i.e. no current is flowing into the coil after removal of the magnet.

Based on this, he derived the mathematical equation:

E=−dΦB​​/dt

Where,

E = Electric Current

ΦB = Magnetic Flux

This equation is called Faraday’s Law of Induction

While Faraday was busy experimenting in London, Joseph Henry made his own discoveries in America (around 1831). He tried to independently explore the concept of electromagnetic induction through a technique similar to that of Faraday.

He used two coils, one primary and one secondary. The primary coil was connected to a battery and the secondary coil was connected to a galvanometer to detect the electric current. He noticed that when the electric current in the primary current was changed (started or paused), there was a deflection in the readings of galvanometer.

As a result, he proved and extended the definition of faraday’s principles and found out concepts related to self-induction and mutual induction that were crucial in development of inductors, motors and transformers.

Hence, we conclude that change in the magnetic fields can induce electric current.