Faraday's and Henry's Experiments-complete information

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Faraday's and Henry's Experiments

Faraday's and Henry's Experiments  were important topics to know before dealing with the concept of Electro magnetic induction . The experiments were carried not only to understand the concept but to show it practically also.

It is because of The importance of Faraday's and Henry's Experiments  that has inspired me to write an article. That's why in today's article I would like to share with you an information related to the Experiments. The Experiments will cover topics like observations and conclusion.

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The Experiments performed by Faraday and Henry  to understand the concept of Electro magnetic induction are described below:

Experiment no 1 :-

Relative motion of a magnet and a conducting coil induces e. m. f in the conducting coil. The arrangement used in the experiment consisted of a coil with a galvanometer and a bar magnet.

Faraday's and Henry's Experiments 

Observations :

some of the observations of this experiment are described below :

1)   It was observed that the galvanometer showed no deflection, when the bar magnet was at rest.

2) When North Pole of the bar magnet moved towards the coil ,galvanometer showed deflection in One direction. The direction indicates the flow of current in the coil.

3)  Again when North Pole of the bar magnet moved away from the coil , galvanometer showed deflection but in the opposite direction. This direction indicates the flow of current in the coil but in the opposite direction.

4) When South Pole of the magnet was brought near the coil, or was moved away from the coil , the galvanometer showed deflection. The galvanometer showed deflection in the opposite direction as compared to that available with the similar movements of the North Pole of the magnet.

5) When the bar magnet was moved faster towards or away from the coil, the deflection of the galvanometer was large. 

Conclusion :

1) Whenever there is a relative motion between a closed coil and a magnet,  induced e. m. f is set up across the coil or induced current flows through the coil.

2) Induced current lasts in the coil so long as the movement of the magnet with respect to the coil continues.

3) If the relative motion between the magnet and the coil is large, induced e. m. f or current is produced in the coil.

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Experiment no 2:-

Relative motion of a conducting coil and a current carrying coil induces e. m. f in the conducting coil. An insulated copper wire wound on a wooden core replaced bar magnet as shown in the figure.

Faraday's and Henry's Experiments no 2

 

Coils were not connected physically with one another. The coil which was connected to the battery was called primary coil P. The coil placed near the first coil connected to a sensitive galvanometer was called secondary coil S. 

Observations :

Some of the observations related to this Faraday's and Henry's Experiment are :

1) It was observed that , when the primary coil was moved towards the secondary coil,  the galvanometer in the secondary coil showed deflection.

2) When the primary coil P was moved away from the coil . It was observed that the galvanometer in the secondary circuit slowed a deflection but in the opposite direction.

3) All the other observations were same as shown in the Faraday's and Henry's Experiment number 1.

The wooden rod used in the experiment was changed with an iron rod. The galvanometer showed larger deflection, when there was a relative motion between the coils. 

Explanation :

When primary coil moves towards or away from the secondary coil , magnetic field or magnetic flux linked with the  secondary coil changes. This change causes the induced e. m. f or current in it till there is relative motion between the coils. Strength of magnetic field improves when iron core is placed in the coil which causes increase in the induced e. m. f. 

Conclusion :

Induced e. m. f and thus current is produced in a nearby conducting coil . When there is a relative motion between a current carrying coil and the conducting coil. 

Experiment no 3 :-

Changing current in a current carrying coil induces e. m. f in a nearby coil without relative motion between the coils.

Faraday's and Henry's Experiments no 3

In this experiment coils C₁ primary and C₂ secondary wound on a wooden core replaced by an iron core are kept at rest. 

Coil C₂ has a galvanometer whereas a battery B is connected to the coil C₁ Through a tapping key TK. 

observations :

1) When a tapping key TK is pressed, galvanometer G shows a momentary deflection. Soon after this, the galvanometer needle returns to zero even if the TK is kept pressed.

2) When the key TK is released, the galvanometer shows momentary deflection again but in the opposite direction.

3) When the wooden bar is replaced by an iron bar , the deflection of the galvanometer increases a lot. 

Explanation :

The "on" or "off" of the current in a coil changes the strength of magnetic field produced by it. When the strength of magnetic field linking with coil 2 changes, an  e. m. f is induced in coil 2.

Induction stops when change in current .  That is we can say change in flux stops. Release of the key brings the current to zero. Decrease in current that is decrease in the strength of magnetic field deflects the needle of the galvanometer in the opposite direction.


when wooden core is replaced with an iron core the strength of magnetic field linking is improved. This replacement makes the galvanometer show more deflection. 

Conclusion :

In this experiment, the coils have no relative motion yet changing current in the primary coil and induces e. m. f  in the secondary coil. 

Conclusion:

This article discussed Faraday's and Henry's Experiments . The article provides you information related the statement of the experiments. The article also discussed about the observations and conclusions related to each experiment.

I hope the Faraday's and Henry's Experiments  were now clear to you. For further information about different types of physics concepts please visit " physics guide ". Share this article to other people on social media aps and help others . Thank you for your visit. Good luck !