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Which conclusion we can obtain by the fact that emf is induced in stationary conductor placed in time varying magnetic field ? Discuss characteristic of induced electric field. |
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Answer» Solution :Faraday verified a fact that an EMF is induced when a conductor is stationary and the magnetic field is changing by numerous experiments. In the case of a stationary conductor, the force on its charges is given by `vecF=q[vecE+(vecvxxvecB)](because v=0)` THUS, any force on the charge must arise from the electric field term E alone. Therefore, to explain the existence of induced emf or induced current, we must assume that a time-varying magnetic field GENERATES an electric field. However, we have to add that electric fields produced by static electric charges have properties different from those produced by time-varying magnetic fields. We learnt that charges in motion (current) can EXERT force/torque on a stationary magnet. Conversely, a bar magnet in motion (or more generally, a changing magnetic field) can exert a force on the stationary charge (due to induced electric field). |
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