- #1
leojun
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why does induced emf change in case of generators but remains constant in case of moving conductor?
Andrew Mason said:If a conducting loop moves through a constant magnetic field there is no induced emf. This is because there is no change in the flux enclosed by the loop.
AM
Ok. So the "moving conductor" is really an expanding loop in which dA/dt = velocity x length of the conductor. In that case [itex]\xi = -\frac{d}{dt}\int\vec{B}\cdot d\vec{A}[/itex] = -Bvl which is constant if v is constant.ehild said:Not the whole loop moves, but one side only in the experiments showing induced voltage in a moving straight piece of metal.
ehild
Yes.Andrew Mason said:Ok. So the "moving conductor" is really an expanding loop in which dA/dt = velocity x length of the conductor. In that case [itex]\xi = -\frac{d}{dt}\int\vec{B}\cdot d\vec{A}[/itex] = -Bvl which is constant if v is constant.
AM
Induced EMF changes in generators because of Faraday's law of electromagnetic induction. According to this law, a changing magnetic field can induce an electric current in a conductor. In generators, this changing magnetic field is created by the motion of the conductor through the magnetic field.
Induced EMF does not change in moving conductors because there is no relative motion between the conductor and the magnetic field. In order to induce an electric current, there must be a changing magnetic field. If the conductor is moving at a constant speed through the magnetic field, there is no change in the magnetic field and therefore no induced EMF.
The magnitude of the induced EMF in generators can be affected by several factors, including the strength of the magnetic field, the speed of the conductor, and the angle between the conductor and the magnetic field. Additionally, the number of turns in the coil and the resistance of the circuit can also affect the induced EMF.
The direction of motion of the conductor can determine the direction of the induced EMF. If the conductor is moving perpendicular to the magnetic field, the induced EMF will be at its maximum. If the conductor is moving parallel to the magnetic field, the induced EMF will be zero. The direction of the induced EMF can also be reversed by changing the direction of motion of the conductor.
Yes, the induced EMF in generators can be increased by increasing the speed of the conductor, increasing the strength of the magnetic field, or increasing the number of turns in the coil. However, there is a limit to how much the induced EMF can be increased, as too much current can damage the generator. Additionally, the resistance of the circuit can also affect the magnitude of the induced EMF.