- #1
Nimbus2000
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I have a confusion regarding Faraday's law of electromagnetism. Consider this diagram
At this instant, the velocity of the rotor is parallel to the field lines, hence, no emf is induced in the rotor. Altetnatively, we can say that the rate of change of flux associated with the rotor is 0 at this instant, hence emf induced is 0.
Also, motional emf is given as E=BlvsinΘ and magnetic flux Φ=BAcosΘ. Now, E=BlvsinΘ=Bl(dx/dt)sinΘ=d(B*l*dx*sinΘ)/dt=d(BAcosΘ)/dt=dΦ/dt. This shows that if we use motional emf formula or the dΦ/dt formula, we arrive at the same result. But what if the conductor is not cutting any magnetic field and there is a change in flux with respect to the loop?
Suppose the middle limb is excited using a dc voltage. All the flux will be enclosed in the limb. Now consider the red loop on the middle limb. If the loop is tilted by some angle, flux through the loop will change since Θ changed. But the loop doesn't cut any flux since all the flux is enclosed in the limb. Will there be emf induced in the loop without cutting of flux lines?
Please help.
At this instant, the velocity of the rotor is parallel to the field lines, hence, no emf is induced in the rotor. Altetnatively, we can say that the rate of change of flux associated with the rotor is 0 at this instant, hence emf induced is 0.
Also, motional emf is given as E=BlvsinΘ and magnetic flux Φ=BAcosΘ. Now, E=BlvsinΘ=Bl(dx/dt)sinΘ=d(B*l*dx*sinΘ)/dt=d(BAcosΘ)/dt=dΦ/dt. This shows that if we use motional emf formula or the dΦ/dt formula, we arrive at the same result. But what if the conductor is not cutting any magnetic field and there is a change in flux with respect to the loop?
Suppose the middle limb is excited using a dc voltage. All the flux will be enclosed in the limb. Now consider the red loop on the middle limb. If the loop is tilted by some angle, flux through the loop will change since Θ changed. But the loop doesn't cut any flux since all the flux is enclosed in the limb. Will there be emf induced in the loop without cutting of flux lines?
Please help.