Is back EMF equal to the induced EMF in self-induction?

In summary, when there is a gradual increase in intensity in a coil with self induction, an emf is induced which creates a back current to oppose the increase. However, the back current may not necessarily be equal in magnitude to the increase in intensity.
  • #1
Entanglement
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In the case of self induction, when the intensity increases gradually an emf is induced which generates a back current " equal in magnitude, opposite in direction " to oppose the increase, so if that is right shouldn't the intensity in the coil Become ZERO till the intensity becomes steady?
 
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  • #2
Well, there are two things going on here. There is the instantaneous current and then there is the rate of change of current. You have to think again at which one provides the magnetic flux and which one provides the change in flux.
 
  • #3
ElmorshedyDr said:
an emf is induced which generates a back current " equal in magnitude, opposite in direction " to oppose the increase,
Where did you get the bolded part (equal in magnitude)? It is not correct.
 
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  • #4
DaleSpam said:
Where did you get the bolded part (equal in magnitude)? It is not correct.
So it doesn't have to be equal ?
 
  • #5
I cannot think of any example where it is equal.
 

1. What is back emf?

Back emf, or back electromotive force, is a phenomenon that occurs when there is a change in magnetic flux through a conductor, resulting in a voltage that opposes the change in current flow. It is commonly seen in electrical motors and generators.

2. How does back emf affect the performance of a motor?

Back emf can have a significant impact on the performance of a motor. It can reduce the motor's speed and torque, as well as increase the power consumption and heat generation. However, it also helps to stabilize the motor's speed and prevent it from overspeeding.

3. What is self induction?

Self induction is the production of an electromotive force in a circuit due to a change in the flow of current through the same circuit. It occurs when a magnetic field is created by the changing current, and the resulting voltage opposes the change in current.

4. How does self induction affect the behavior of an inductor?

Self induction is a fundamental property of inductors and is responsible for their ability to store energy in the form of a magnetic field. It also causes inductors to resist changes in current flow, making them useful in regulating and filtering electrical circuits.

5. How can back emf and self induction be minimized?

Back emf and self induction can be minimized by using components such as flyback diodes or snubber circuits, which provide a path for the induced voltage to dissipate. Additionally, using components with lower inductance values or higher switching frequencies can also help reduce their effects.

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