As I said in your other thread, try starting with wikipedia.Amr Elsayed said:Hello all, I have got a hard time thinking of what back E.M.F is. Does it appear only at the moment of switching and closing the circuit ? why it's even there and what is its relation with E.M.F .
If some one can provide me with a brief and good source that elegantly explains the whole thing I will be grateful.
Regards
Back EMF, or back electromotive force, is a voltage that is generated in a coil of wire when the current through the coil is changed. This voltage is opposite in direction to the voltage that was originally applied to create the current.
Back EMF plays a crucial role in many electrical and electronic systems, particularly in motors and generators. It can affect the performance and efficiency of these systems, and understanding it can help in designing and optimizing them.
Lenz's Law states that the direction of an induced current in a conductor will be such that it opposes the change that caused it. Back EMF is a direct result of this law, as the induced voltage in the coil opposes the change in current that created it.
In most cases, back EMF is not harmful to electronic devices. In fact, it can be beneficial in certain applications, such as inductive loads, where it helps to protect the device from damage due to sudden changes in current.
Back EMF can be measured using a voltmeter or an oscilloscope. By connecting these instruments across the coil of wire, the voltage generated by the back EMF can be observed and analyzed.