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Magnetomotive force (not 'magneticmotive force') is analogous to electromotive force, in the same way that magnetic flux is analogous to current, and reluctance is analogous to resistance. Mmf, flux, and reluctance also have the same 'Ohm's law' relationship as emf, current, and resistance. It is mmf that sets up the magnetic flux; it is the emf that sets up the current.
One point worth noting is that despite mmf being measured in amperes (the product of the current flowing through a coil and the number of turns), it is still analogous to emf, and not current!
Wiki User
∙ 12y ago
Wiki User
∙ 7y agoOhm's Law does not exist for magnetic circuits, only for electric circuits.
The analog of Ohm's Law in magnetic circuits is called Hopkinson's Law.
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How initially voltage build up in an alternator by residual magnetism?
The residual flux will help the phenomenon of changing flux. So that emf generation takes place.
A cell of emf 3.0 volts and internal resistance of 0.01 ohm is connected through an ammeter of 0.05-ohm internal resistance to a 5.0 rheostat by wire having a total resistance of 0.85-ohm?
total voltage = 4.5V, total resistance = 3.5 ohms, loop current = 4.5V / 3.5 ohms = 1.286Atotal voltage = 9V, total resistance = 4 ohms, loop current = 9V / 4 ohms = 2.25Atotal voltage = 13.5V, total resistance = 4.5 ohms, loop current = 13.5V / 4.5 ohms = 3Aetc.There is no solution to your problem conditions.
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
If A generator has an armature resistance of 0.6 ohms and when connected to a load of 40.9 ohms passes a current of 3.5 A what is the terminal voltage and generated EMF?
145.25 v
How initially voltage build up in an alternator by residual magnetism?
The residual flux will help the phenomenon of changing flux. So that emf generation takes place.
How do you find voltage when amps is known?
You don't. If you know how many Amperes in an electrical circuit and also what the total resistance in the circuit is, then EMF (Volts) = current (Amps) x resistance (in Ohms). EMF stands for Electromotive Force, and its unit of measure is the Volt.
A cell of emf 3.0 volts and internal resistance of 0.01 ohm is connected through an ammeter of 0.05-ohm internal resistance to a 5.0 rheostat by wire having a total resistance of 0.85-ohm?
total voltage = 4.5V, total resistance = 3.5 ohms, loop current = 4.5V / 3.5 ohms = 1.286Atotal voltage = 9V, total resistance = 4 ohms, loop current = 9V / 4 ohms = 2.25Atotal voltage = 13.5V, total resistance = 4.5 ohms, loop current = 13.5V / 4.5 ohms = 3Aetc.There is no solution to your problem conditions.
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
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 .
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.
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!
Another name for EMF?
"Potential difference" or "Voltage".
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
What unit measures EMF?
EMF stands for Electro-Motive Force, commonly known as Voltage, measured in Volts.
