EMF (induced, back and whichever types) (1 Viewer)

[sugaryblue]

I am so confused with it!

What are the differences for induced and back?

How to find the direction of the above?

and etc

just any information about them

What is emf exactly?

please help me thanks

 

[Ragerunner]

induced emf and back emf is the same thing

by lenz law "the direction of the emf is such that it creates a magnetic field that opposes the change that caused it"

or something like that

the back emf is the emf that opposes the induced emf.

emf is the electromotive force

so as the speed of the motor increases more back emf occurs which ultimately limits the speed of the motor spinning

 

[sugaryblue]

Originally posted by Ragerunner
induced emf and back emf is the same thing

by lenz law "the direction of the emf is such that it creates a magnetic field that opposes the change that caused it"

or something like that

the back emf is the emf that opposes the induced emf.

emf is the electromotive force

so as the speed of the motor increases more back emf occurs which ultimately limits the speed of the motor spinning

I have been told that emf is not exactly a 'force', it's voltage of somekind.

what does it do?

 

[CHUDYMASTER]

the back emf is the emf that opposes the induced emf.

Eh, think you meant applied emf.

This is not always the case however. You see, in some instances, there is no applied voltage and the induced (back) emf is the only thing which drives the current. Take a very simple example of moving a magnet toward a solenoid. The north side goes toward one end of the solenoid and to oppose this changing field, a north pole is set up on that side to oppose it. Since you now know one of the poles, you can use your right-hand grip rule to tell the direction of induced current.

 

[Constip8edSkunk]

EMF is not a force, they just named it wrong. From my loose grasp of this concept, it just describes the state of charge separation in a conductor that may or may not cause a flow of currentc depending on how the conductor is set up. It is basically the potential difference or voltage.

Induced EMF is the back EMF when say a motor rotates in a magnetic field. the emf induced in the coil opposes the applied emf from the powersource, and is hence called the back emf. In these cases, i find using the right hand palm rule is easier.