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Counter EMF (Electromotive Force) voltage is the voltage generated by an electric motor or generator that opposes the applied voltage when the device is in operation. It arises due to the motion of the conductor in a magnetic field, following Faraday's law of electromagnetic induction. This opposing voltage limits the current flowing through the motor or generator, helping to regulate its speed and efficiency. Essentially, counter EMF acts as a self-regulating mechanism in electrical machines.
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What the counter emf of a motor is always less than applied armature voltage.explain?
The counter electromotive force (counter EMF) of a motor is always less than the applied armature voltage because the motor requires a certain amount of voltage to overcome its internal resistances and inductances, as well as to produce torque. When the motor starts, the armature current is high, leading to a significant voltage drop due to resistance. As the motor speeds up, the counter EMF increases, but it never reaches or exceeds the applied voltage, as some voltage is always required to maintain current flow and overcome losses like friction and heat. Thus, the counter EMF is always a fraction of the applied voltage.
How does voltage drop related to impressed emf?
Voltage drop is resultant of IR ie current and the line resistance, not dependent on impressed 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!
Why do you measure emf with a potentiometer not with voltmeter?
EMF (E''electromotive Force'') is another term for Volts, hence the E in electronic formulas and EMF is measured with a volt meter. A potentiometer is not a meter at all, it is a variable resistor
what will be the emf of the battery when Four cells each of emf E are joined in parallel to form a battery?
E. Joined in parallel, the voltage (or electromotive force, "emf") isn't additive. You'd get four times the current, or four times the life of a single battery, but it would have the same voltage.
What the counter emf of a motor is always less than applied armature voltage.explain?
The counter electromotive force (counter EMF) of a motor is always less than the applied armature voltage because the motor requires a certain amount of voltage to overcome its internal resistances and inductances, as well as to produce torque. When the motor starts, the armature current is high, leading to a significant voltage drop due to resistance. As the motor speeds up, the counter EMF increases, but it never reaches or exceeds the applied voltage, as some voltage is always required to maintain current flow and overcome losses like friction and heat. Thus, the counter EMF is always a fraction of the applied voltage.
Opposition to voltage changes in a wire is called what?
Opposition to voltage changes in a wire is called back EMF or counter EMF.See related links below.
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
How does voltage drop related to impressed emf?
Voltage drop is resultant of IR ie current and the line resistance, not dependent on impressed emf
What is the difference between CEMF and EMF?
Only the relative direction they are moving. EMF, measured in Volts, travels along a conductor, perhaps because a magnetic field has built up around the conductor. When that magnetic field collapses, CEMF, or counter-EMF is generated in the conductor, and it travels in the opposite direction of the original EMF, countering the original flow of electricity. EMF is Electromotive Force, and is one component of measuring electricity. EMF is measured in Volts, and represents the 'pressure' moving the electricity along.
It can be said that pressure and electromative force are the same?
There is analogy between pressure and EMF or voltage. What pressure is to the liquids, EMF or voltage is to electric current. But, of course, they are not the same.
Can the terminal voltage of a battery be larger than its emf?
the voltage of a battery could be larger than the emf if you are to charge the battery, in that case V=E+Ir .
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!
Is emf current greater than current?
EMF is electromotive force. It is another name for voltage. Voltage is electric potential in joules per coulomb. Current is electric flow, in amperes. Amperes are coulombs per second. Voltage and current are not the same thing, and "emf current", or "voltage current" does not make sense.
Another name for EMF?
"Potential difference" or "Voltage".
What unit measures EMF?
EMF stands for Electro-Motive Force, commonly known as Voltage, measured in Volts.
What is the electric pressure?
Electro motive force = EMF = Voltage.
