Fleming’s Left And Right Hand Thumb Rules 2023:


The left and right thumb rules were established by (John Ambrose) Fleming in the late 19th century.

Whenever a current-carrying conductor comes under a magnetic field, a force will act on the conductor. The direction of this force can be found using Fleming’s left-hand rule (also known as ‘Fleming’s left-hand rule for motors’).

Similarly, if a conductor is forced under a magnetic field, there will be an induced current in that conductor. The direction of this force can be determined using Fleming’s right-hand rule.

In both Fleming’s left-hand and right-hand laws, there is a relationship between magnetic field, current, and force. This relationship is determined by Fleming’s left-hand rule and Fleming’s right-hand rule, respectively.

These principles do not determine the magnitude but instead indicate the direction of any of the three parameters (magnetic field, current, force) when the direction of the other two parameters is known.

Fleming’s left-hand rule applies mainly to electric motors and Fleming’s right-hand rule applies mainly to electric generators.

 Fleming’s Left Hand Rule:

It is found that whenever a current-carrying conductor is placed inside a magnetic field, a force acts on the conductor in a direction perpendicular to both the current and the direction of the magnetic field.

In the figure beneath, a part of a guide of length ‘L’ is put upward in a uniform even attractive field of solidarity ‘H’, delivered by two attractive posts N and S. If the current ‘I’ is going through this guide. The extent of the power following up on the guide is:

Place your left hand in front of each other with the index finger, second finger and thumb at right angles. If the index finger represents the direction of the field and the other finger represents the current, then the thumb represents the direction of the force.

As current flows through a conductor, a magnetic field is created around it. A magnetic field can be visualized by considering the number of closed magnetic lines of force around a conductor.

The direction of the magnetic lines of force can be determined by Maxwell’s corkscrew principle or the right-hand grip principle.

According to these principles, the direction of the magnetic lines of force (or lines of flux) is clockwise if the current is flowing away from the observer, i.e. if the direction of current through the conductor is inward from the reference plane as in is shown. statistics.

Presently on the off chance that a flat attractive field is applied remotely to the guide, these two attractive fields for example the field around the guide because of the ongoing coursing through it and the remotely applied field connect with one another. will

We see in the figure that the attractive lines of power of the outside attractive field are N to S posts from left to right.

The magnetic lines of force of the external magnetic field and the magnetic lines of force due to the current in the conductor are in the same direction above the conductor, and they are in the opposite direction below the conductor.

Therefore, there will be a larger number of parallel magnetic lines of force above the conductor than below the conductor.

Consequently, a small area above the conductor will have a large concentration of magnetic lines of force. Since the magnetic lines of force are no longer straight lines, they are in tension like a stretched rubber band.


As a result, there will be a force that will move the conductor from a more concentrated magnetic field to a less concentrated magnetic field, i.e. downwards from the current position.

Now if you observe the direction of current, force and magnetic field in the above description, you will see that the directions are according to Fleming’s left hand rule.

Fleming’s Right Hand Rule:

According to Faraday’s law of electromagnetic induction, whenever a conductor moves within a magnetic field, it will induce an induced current. If this conductor is forced to move within a magnetic field, there will be a relationship between the applied force, the magnetic field, and the direction of the current.

The relationship between these three directions is determined by Fleming’s right-hand rule.

This standard states, “Hold the right hand with the principal finger, second finger, and thumb at right points to one another. In the event that the pointer addresses the heading of the line of power, the thumb focuses toward movement or applied force.” focuses, then, at that point, the other finger focuses toward the prompted current.”


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