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When an AC generator provides an alternating current to the coil will induce the magnetic filed around it. This is called primary magnetic field. The impedance is nothing but the opposition to the current flow. The coil will have resistance as well as inductance. When this coil is brought to near any conducting material, due to the primary magnetic filed the eddy currents will develop in the material. The magnetic filed which will induce in the material is called secondary magnetic field due to the eddy current secondary magnetic field will try to oppose the primary magnetic field due to any change in the eddy current pattern. Once primary magnetic filed gets affected in the coil definitely there will be a change in impedance in terms of resistance and inductance.
You can think of eddy currents as current flowing in the wrong direction (across laminations in Transformers, for example). This energy is effectively lost, causing a higher loss, increasing the resistance. Eddy currents will have a minimal effect on impedance, since this is typically much larger than the resistance (note impedance is the resistance and reactance of the coil, reactance will typically dominate).
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Can a 12vac coil be operated by 24vdc?
no, in an ac circuit the coil provides impedance but the DC coil needs some resistance to limit the current
Why is there a difference in current in a coil when you apply dc voltage and then AC voltage to it?
A coil has both resistance and inductance. When you apply a d.c. voltage, the opposition to current is the resistance of the coil. When you apply an a.c. voltage, the opposition to current is impedance -the vector-sum of the coil's resistance and its inductive reactance. Inductive reactance is proportional to the inductance of the coil and the frequency of the supply.
How do you measure speaker impedance?
The real impedance is the resistance in ohms more 20%. A coil resistance of 6,7 ohms X 1.20 = an impedance of 8.04 ohms. If the voice-coil had exactly 8 ohms, the impedance would be 9.6 ohms and the sound would be unclear, tending to more basses.
How choke coil limit current to the fluorescent tube?
A choke coil, also known as a ballast, limits the current to a fluorescent tube by providing a high impedance to the flow of current. This high impedance restricts the current flowing through the tube, allowing it to operate within its required current range. The choke coil also helps regulate the starting voltage and stabilize the operation of the tube.
Does the resistance of heater coil remains same when current flows through it?
Typically resistance rises with temperature.
Can a 12vac coil be operated by 24vdc?
no, in an ac circuit the coil provides impedance but the DC coil needs some resistance to limit the current
Why is there a difference in current in a coil when you apply dc voltage and then AC voltage to it?
A coil has both resistance and inductance. When you apply a d.c. voltage, the opposition to current is the resistance of the coil. When you apply an a.c. voltage, the opposition to current is impedance -the vector-sum of the coil's resistance and its inductive reactance. Inductive reactance is proportional to the inductance of the coil and the frequency of the supply.
What happens to the resistance when the frequency is doubled?
Impedance of a coil or a capacitor does depend on the excitation frequency,but resistance has no relationship to frequency.
What is the reciprocal of the power factor?
impedance/resistance
How do you measure speaker impedance?
The real impedance is the resistance in ohms more 20%. A coil resistance of 6,7 ohms X 1.20 = an impedance of 8.04 ohms. If the voice-coil had exactly 8 ohms, the impedance would be 9.6 ohms and the sound would be unclear, tending to more basses.
How choke coil limit current to the fluorescent tube?
A choke coil, also known as a ballast, limits the current to a fluorescent tube by providing a high impedance to the flow of current. This high impedance restricts the current flowing through the tube, allowing it to operate within its required current range. The choke coil also helps regulate the starting voltage and stabilize the operation of the tube.
Why in coil power factor is low?
A coil of wire acts as an inductor; it will have a very small resistance, and a relatively large inductance. Power factor is effectively the resistance divided by the impedance (made up of resistance and inductance), so the larger the inductance relative to the resistance, the lower the power factor will be.
What is the relationship between frequency and the size of a transformer?
Basically the characteristics of a transformer depends on the impedance(resistance) and on the coupling of its primary and secondary coils. The impedance of a coil depends on the frequency, as the frequency increases you need less volume of iron core and less number of turns in the coil for a given impedance, then reducing the size of the transformer.
Does the resistance of coil remain same through out of experiment why?
The resistance of the coil does not remain the same throughout the experiment because the voltage across and the current is varied.
How yo calculate angle of lag in a inductive coil circuit?
There are several ways of doing this, but it depends on what information you have to start with. One way is to find the impedance, using a voltmeter and an ammeter (impedance will be the product of the two readings), and the resistance using an ohmmeter (or, better still, a Wheatstone Bridge) and, then, use the equation:cos (phase angle) = resistance / impedance
Does the resistance of heater coil remains same when current flows through it?
Typically resistance rises with temperature.
Does resistance of heater coil remains same when current flows through it?
Typically resistance rises with temperature.
