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Kiran shakoor Roll no 07-05 BS(IT)3rd. Motional EMF:. The emf induced by the motion of a conductor across a magnetic field is called motional emf
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Kiran shakoor Roll no 07-05 BS(IT)3rd
Motional EMF: • The emf induced by the motion of a conductor across a magnetic field is called motional emf • When a conductor is moved across a magnetic field an emf is induced between its ends.the emf of the moving conductor is similar to that of a battery
Consider a length l of conductor moving to the right in a magnetic field that is into the diagram. Positive charges in the conductor will experience an upward force and negative charges a downward force
The net result is that charges will “pile up” at the two ends of the conductor and create an electric field E
When the force produced by E becomes large enough to balance the magnetic force, the movement of charges will stop and the system will be in equilibrium.
When the conductor moves it acts as source of emf The motional emf ε will equal to the potential difference b/w the two ends of conductor in this equilibrium state ε = ∆V
The magnetic force will be FB=qvB The electric force will be FE=qE Since both are equal FB=FE so qvB=qE Both q will cancel each other E=vB
E=-ΔV/L ΔV=-LE E=vB The motional emf is ε=ΔV=-LvB The magnitude is ε=LvB