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All magnetic materials require some energy before they will operate. You can think of it as the price of admission. In an electrical transformer, the excite current is actually a composite of the energy which is lost due to eddy currents in the magnetic material as well as hysteresis losses of the material.
Excite current is both frequency and voltage dependent. Instead of saying, "before my husband will do anything I have to bake him a cake", you could say"before my transformer runs at 115Vinput, I have to supply x milliAmps of excite current just to get the core going." A special class of Transformers known as CT's or Current Transformer's works in much the same way, except their voltage is reflected off the load instead of coming directly in through the primary.
This energy is dissipated as heat. In power transformers, the concern is energy lost with no load connected on the output. In current transformers, the concern is the varying loss of accuracy due to the highly non-linear nature of excite current, especially at low excite levels.
What else can I help you with?
What is len'z principle?
Lenz's principle states that the direction of an induced electromotive force (emf) and the resulting current in a closed loop is such that it opposes the change in magnetic flux that produced it. This principle is a consequence of the conservation of energy and is commonly expressed in the context of electromagnetic induction. Essentially, if a magnetic field through a conductor changes, the induced current will flow in a direction that creates a magnetic field opposing that change. This principle is crucial in understanding how devices like generators and transformers operate.
How do you arrive at nernst equationwhere does it come from?
The Nernst equation is derived from the principles of thermodynamics and electrochemistry, specifically relating to the relationship between Gibbs free energy and cell potential. It expresses how the electromotive force (EMF) of an electrochemical cell changes with concentration and temperature. Mathematically, it relates the standard cell potential to the concentration of reactants and products using the equation: ( E = E^\circ - \frac{RT}{nF} \ln Q ), where ( E ) is the cell potential, ( E^\circ ) is the standard cell potential, ( R ) is the universal gas constant, ( T ) is the temperature in Kelvin, ( n ) is the number of moles of electrons transferred, ( F ) is Faraday's constant, and ( Q ) is the reaction quotient. This equation allows for the calculation of cell potential under non-standard conditions.
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!
How can current be induced in a conductor?
Current can be induced in a conductor by changing the magnetic field around it. This change in magnetic field creates an electromotive force (EMF) within the conductor, which in turn causes the flow of current. This phenomenon is known as electromagnetic induction and is the basis for the operation of generators and transformers.
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.
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'.
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.
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 happens when magnetic flux changes?
When magnetic flux changes, an electromotive force (emf) is induced in a conductor or coil according to Faraday's Law of electromagnetic induction. This induced emf can cause current to flow in a closed circuit. This phenomenon forms the basis of how generators produce electricity and how transformers work in electrical systems.
Why induced current in a coil opposes the EMF producing it?
lenzs law
What is the statment of lenz law?
The direction of an induced emf or current is such that the magnetic field created by the induced current opposes the change in magnetic flux that created the current.
What does the lenz law state?
The direction of an induced emf or current is such that the magnetic field created by the induced current opposes the change in magnetic flux that created the current.
Why you use diode to find indused emf?
A diode is used to find induced electromotive force (emf) because it allows current to flow in one direction, which helps in rectifying the induced voltage signal. When measuring induced emf in a circuit, the diode can help in isolating the effect of the induced voltage by blocking reverse current, thus providing a clearer indication of the magnitude and direction of the induced emf. This is particularly useful in experiments involving alternating current (AC) signals where the direction of current can change. Overall, the diode simplifies the measurement process by ensuring only the desired signal is registered.
Does the induced emf in a circuit depend on the resistence of the circuit?
The induced emf in a circuit is not directly dependent on the resistance of the circuit. It is primarily determined by the rate of change of magnetic flux through the circuit. However, the resistance of the circuit can affect the current flow and ultimately impact the magnitude of the induced emf through Ohm's law (V = IR).
