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In a dc motor the voltage generated in the armature acts against the supply voltage. The current is the voltage difference divided by the armature resistance.
If the rotor is turned faster so that the back emf exceeds the supply voltage, the current goes the other way and the motor has become a generator.
What else can I help you with?
Does motional emf call induced emf?
yes indused emf is also called motional 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.
Difference between back EMF and induced EMF?
An induced electromotive force (emf) is an induced voltage. Voltage (emf) causes current flow, and this induced voltage will cause a current that is called the induced current.We might also add that the induced current will cause a magnetic field to expand about the current path, and this field will "sweep" the conductor. The sweeping of the conductor by that expanding magnetic field will set up an emf that will oppose the emf that was creating it.CommentTechnically, there is no such thing as an 'induced current'. It is voltage that is induced. Any current flows as a result of that induced voltage being applied to a load. But that current is certainly NOT induced!
What are the Example each for self induced and mutually induced emf?
if an emf is induced in a coil due to the current flowing through itself is called SELF INDUCTANCE. on the other hand if an emf is induced on another coil due to the current flowing through the previous coil then it is called MUTUAL INDUCTANCE. suppose there are two coils A and B a current is flowing through A. now if the flux produced due to this current induce an emf on the same coil A, then it is SELF INDUCTANCE, and if it produce emf on B, then it is MUTUAL INDUCTANCE due to coil A.
Why induced current in a coil opposes the EMF producing it?
lenzs law
What is the main cause for the coefficient of coupling of a transformer being less than unity?
initially the induced emf i.e.,self inductance is high than mutually induced emf in the other .....so coefficient of coupling is high
Does motional emf call induced emf?
yes indused emf is also called motional 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 emf induced in a motor's coil that tends to reduce the current in the coil of the motor?
BACK emf induced in a motor's coil that tends to reduce the current in the coil of the motor. The answer should be 'back'.
Difference between back EMF and induced EMF?
An induced electromotive force (emf) is an induced voltage. Voltage (emf) causes current flow, and this induced voltage will cause a current that is called the induced current.We might also add that the induced current will cause a magnetic field to expand about the current path, and this field will "sweep" the conductor. The sweeping of the conductor by that expanding magnetic field will set up an emf that will oppose the emf that was creating it.CommentTechnically, there is no such thing as an 'induced current'. It is voltage that is induced. Any current flows as a result of that induced voltage being applied to a load. But that current is certainly NOT induced!
What is Back emf of DC motor?
In dc motor, the armature conductors are revolving in the magnetic field and emf is induced in the armature conductors. The direction of the induced emf is in opposite direction to the applied voltage as per Flemings left hand rule. So, the induced emf in motor is called as back emf or counter emf. Vydehi
When a conductor cuts magnetic flux an emf is induced in the conductor. This is known as?
faraday law
What is the induced emf in case (a)?
In case (a), the induced emf is the electromotive force generated in a coil or conductor due to a changing magnetic field.
In colomn answer of difference between statically indused emf and dynamicaly indused emf?
Statically induced emf is produced by the relative motion between a conductor and a magnetic field, while dynamically induced emf is generated due to a change in the magnetic field strength experienced by a conductor. Statically induced emf does not require any physical movement of the conductor, while dynamically induced emf is produced when the magnetic field changes over time.
Can emf induced without an alternating magnetic flux?
No. EMF can only be induced in a wire by a varying magnetic flux. It does not have to be alternating, but it must be varying.
Difference between statically and dynamically induced emf?
STATICALLY INDUCED EMFThe emf induced in a coil due to change of flux linked with it (change of flux is by the increase or decrease in current) is called statically induced emf.Transformer is an example of statically induced emf. Here the windings are stationary,magnetic field is moving around the conductor and produces the emf.DYNAMICALLY INDUCED EMFThe emf induced in a coil due to relative motion of the conductor and the magnetic field is called dynamically induced emf.example:dc generator works on the principle of dynamically induced emf in the conductors which are housed in a revolving armature lying within magnetic field
How can you say that ac emf is induced in the coil?
When we place a current carrying conductor in a magnetic field emf is induced in a coil. we can knoe it by connecting voltmeter.
What is the induced electromotive force (EMF) in this loop?
The induced electromotive force (EMF) in a loop is the voltage generated when there is a change in magnetic field within the loop.
Is lenz law used to find induced EMF's?
It's primary usage is to determine the nature of an induced EMF from changes in the magnetic flux through a circuit. However, you must use Faraday's Law (and a unit conversion factor) to determine the SIZE of such an EMF.
