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What is Fleming,s Right hand rule?How do we apply it in an electric motor?

The direction of induced current produced in a straight conductor (or wire) moving in a magnetic field is given by Fleming’s right-hand rule. According to Fleming’s right-hand rule : Hold the thumb, the forefinger and the centre finger of your right-hand at right angles to one another. Adjust your hand in such a way that forefinger points in the direction of magnetic field, and thumb points in the direction of motion of conductor, then the direction in which centre finger points, gives the direction of induced current in the conductor.

     Suppose the direction of magnetic field is directed from east to west as shown by arrow AB in the given figure, and the direction of motion of conductor is vertically downwards, as shown by the arrow AC in the figure  .



Then to find out the direction of induced current in the conductor, we hold the thumb, the forefinger and centre finger of our right-hand mutually at right angles to one another. We adjust the right hand in such a way that the forefinger points from east to west (to represent the magnetic field), and the thumb points vertically downwards (to represent the direction of motion), then we will find that our centre finger points towards northand this gives the direction of induced current. Thus, the induced current in this case will be towards north as represented by arrow AD in the figure. Fleming’s right-hand rule is also called dynamo rule.


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