Mell Can the back emf in an inductor be in the same sense as the emf of source?
No. It is not necessary. Back emf is not called so because it produces a current that is opposite to the direction of current already flowing in the inductor. It is called back emf because it tends to produce a current that opposes the change in current already flowing in the inductor.
Can the emf in a conductor be in the same sense as the emf of source which gives the inductor its magnetic energy?
Can the end in a conductor be in the same sense as the emf of the source which gives the inductor its magnetic energy? If any voltage source is connected across any inductor the voltage across the source and inductor will always be the same.
What is back emf in an inductor and how does it control the flow of electricity in a circuit?
The back EMF is produced because the changing current in the inductor causes a changing magnetic field around it and the changing magnetic field causes, in turn, an EMF to be induced back into the inductor. This process is called SELF INDUCTION.
What is the difference between emf and back emf?
If an open coil is subjected to a variable magnetic field, at the ends of the coil a potential difference is induced which is called induced emf. If a coil is connected to an emf source and switched on, the rising current will produced an variable magnetic field which in turn produces an emf. It is called back emf.
What is back EMF in inductor?
Counter-electromotive force (counter EMF, CEMF), also known as back electromotive force (back EMF), is the electromotive force (voltage) that opposes the change in current which induced it. CEMF is the EMF caused by magnetic induction (see Faraday’s law of induction, electromagnetic induction, Lenz’s law).
Why back EMF is less than applied voltage?
Back EMF is less than the applied voltage because of the resistance of the armature winding. In the above circuit the Back emf can be written as, Therefore, Now in the above equation if the value of current is negative then back emf can be higher than the applied voltage, which is the case for the generators.
What causes an inductor to produce a back EMF?
The source produces a current. That (changing) current causes the inductor to produce a back emf. The back emf limits (but doesn’t eliminate) the current produced by the source. If it eliminated the current, then there would be no back emf. The two things don’t oppose each other so much as they balance each other.
What happens when the back EMF equals the applied EMF?
So the rate of current increase rises until the back emf of the inductor equals the applied emf. Additionally, since nothing prevents instantaneous changes in rate of change of current, the circuit can equilibrate to steady state (of constantly increasing current) instantly.
What is the difference between the generator and the back EMF?
The generator output of a motor is the difference between the supply voltage and the back emf. The back emf is zero when the motor is first turned on, meaning that the coil receives the full driving voltage and the motor draws maximum current when it is on but not turning.
Is the back EMF better than the diode?
In the case of the MOV it shorts across its leads when the back EMF exceeds its breakdown voltage, so it is no better than the diode. The TVS keeps a fixed voltage on breakdown and the time the current flows for is reduced. It is also possible that the freewheeling diode can damage the relay.