Questions tagged [electromagnetic-induction]

This tag is for questions regarding to electromagnetic induction, a process in which a conductor is put in a particular position and magnetic field keeps varying or magnetic field is stationary and a conductor is moving. Electromagnetic Induction was first discovered way back in the 1830’s by Michael Faraday.

Electromagnetic Induction is a current produced because of voltage production (electromotive force) due to a changing magnetic field.
Mathematically, the induced voltage can be given by the following relation:$$e = N × \dfrac{dΦ}{dt}$$Where,

  • $e$ is the induced voltage (in volts)
  • $N$ is the number of turns in the coil
  • $Φ$ is the magnetic flux – the amount of magnetic field at a surface (in Webbers)
  • $t$ is the time (in seconds)

Electromagnetic induction has found many applications, including electrical components such as inductors and transformers, and devices such as electric motors and generators.

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Voltmeter reading accross 1/4th of ring where current is due to changing magnetic field

There is a ring with constant changing perpendicular magnetic field producing emf = 12 V across the ring. (whole ring is an uniform resistance) If we put an ideal voltmeter connecting 1/4th of the ring then voltange showing will be? A) 3 V (if we…
Mitul Agrawal
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How magnetic induction works

What exactly is happening to the electrons inside the wire while it is moving quickly downwards within the magnetic field? Why do electrons move in one direction if the wire is being pushed down? I don't care what direction electrons move. I want to…
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Does induced EMF depend on resistance of the coil?

Does the electromagnetically induced emf in a coil depend on the resistance of the coil? Why?
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The fate of a bar magnet released in an infinitely long copper tube

A bar magnet is released under gravity inside a long copper tube along the axis of the tube. The answer is given (edit :) it moves with constant velocity. But I don't understand how. My research : The bar magnet is falling with an acceleration of…
Ishaan
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Polarity in a magnetized Möbius strip

When a flat iron or Alnico washer is magnetized one of the faces develops a north polarity and the other, south. The geometric shape here is simple. However, when a standard Möbius strip (or one of given thickness, radii of curvature and torsion of …
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Faraday induction law - surface clarification

Faraday's law states, $$emf = \oint \mathbf{E} \cdot \mathrm{d}\boldsymbol{l} = - \frac{\mathrm{d}}{\mathrm{d}t} \int \mathbf{B} \cdot \mathrm{d}\mathbf{s}$$ The typical surface we see used to elucidate this law is a single-turn coil of wire like…
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How does change in magnetic flux density only induce EMF?

Faraday's law states that Induced EMF is equal to rate of change of magnet flux linkage. Magnetic flux linkage is equal to the product of number of turns, area, and magnetic flux density. So EMF can be induced by changing the area, or magnetic flux…
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Electromagnetic induction with light bulbs

I chose C as the voltage, which was initially split between the two lamps, will only be "used" by lamp 1, thus increasing the brightness. However, the answer is D.
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From where is energy got in electromagnetic induction?

I've been reading about electromagnetic induction and while the concept of transfering energy via magnetic field is intuitive, what I'm confused about is, where is the current or energy got from? I know that the electromagnetic force is defined…
mavavilj
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Why does electromagnetic induction happen?

What is the reason behind electromagnetic induction? Why is a current induced in a changing magnetic field? I am only a highschool sophomore and therefore not well versed with Lorentz force or anything of the sort. I do know about flemings left hand…
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Induced Electric Field (E-field) Around a Toroidal Coil or Toroidal Cylinder Coil

Im trying to figure out the formula/formulas that describes the induced electric field around a toroidal coil or a toroidal cylinder in case dB/dt=!0. If I remember correctly there was a very good paper that I found a few years ago in which the…
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Bar magnet dropped through a solenoid - when does the peak voltage occur?

For a bar magnet dropped through a solenoid, we know that the graph of the induced emf looks like this: This source says that position A is just before the magnet enters the solenoid, B is when the magnet is in the middle of the solenoid, and C is…
Freddie
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Why doesn't current cancel in a generator?

I am a little confused about the application of Faraday's law in a generator. If we imagine a magnet attached to a wheel (which spins when water falls on it) next to a coil, as the magnet spins around, current will be generated due to…
Jay
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Why are there two concave poles in an AC generator

If we suppose that the magnetic poles in the AC generator are regular rectangular bar magnets, then the field lines are supposed to be straight lines as in the photo below: And then the direction of velocity will be inclined with an angle to flux…
user3407319
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Working principle of inverter

I got project on the working of inverter from school. I know this that DC inverter has an alternator switch which constantly changes its direction so that magnetic field is produced in primary coil due to which current is induced in secondary coil…
arun483
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