In this article, we will derive an expression for induced emf in a rod rotating in a uniform magnetic field. So let’s get started…
Motional EMF in rotating rod Class 12

Consider a metallic rod of length , which is rotating with angular velocity in a uniform magnetic field , the plane of rotation is perpendicular to the magnetic field.
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- Motional EMF, and energy consideration class 12
A rod may be supposed to be formed of a large number of small elements. Consider a small element of length at a distance from the center. If is the linear velocity of this element, then the area swept by the element per second is . According to Faraday’s law of electromagnetic induction. EMF induced in the rod due to this small area is given as
But
The emf induced across the rod
Current induced in the rod
Current induced in rod,
The power dissipated through the circuit is
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