0
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).
What else can I help you with?
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 does a coil react to AC?
When an alternating current (AC) passes through a coil, it generates a magnetic field that constantly changes direction and magnitude in sync with the AC frequency. This phenomenon induces an electromotive force (EMF) in the coil due to self-induction, which can cause the coil to resist changes in current flow. The coil's impedance, which combines resistance and inductive reactance, affects how much current flows through it. As a result, the coil can store energy in its magnetic field, leading to phase differences between voltage and current in the circuit.
How does coil resistance affect angle between the current in a resistor and the current in an inductor?
Coil resistance affects the phase angle between the current in a resistor and the current in an inductor by influencing the total impedance of the circuit. In an inductive circuit, the presence of resistance causes the current to lag behind the voltage, reducing the phase difference. Higher resistance results in a smaller angle, as the resistive component (which is in phase with the voltage) becomes more significant compared to the inductive reactance, which causes the current to lag. Consequently, the angle approaches zero as resistance increases, indicating that the current becomes more aligned with the voltage.
What is the value of resistance ot coil having impedance of 50ohm connected across 240v at 0.8 p.f?
To find the resistance of a coil with an impedance of 50 ohms connected across 240V at a power factor of 0.8, we can use the formula for power factor: ( \text{p.f.} = \frac{R}{Z} ), where ( R ) is the resistance and ( Z ) is the impedance. Rearranging gives ( R = \text{p.f.} \times Z ). Thus, ( R = 0.8 \times 50 , \text{ohms} = 40 , \text{ohms} ). Therefore, the resistance of the coil is 40 ohms.
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 does a coil react to AC?
When an alternating current (AC) passes through a coil, it generates a magnetic field that constantly changes direction and magnitude in sync with the AC frequency. This phenomenon induces an electromotive force (EMF) in the coil due to self-induction, which can cause the coil to resist changes in current flow. The coil's impedance, which combines resistance and inductive reactance, affects how much current flows through it. As a result, the coil can store energy in its magnetic field, leading to phase differences between voltage and current in the circuit.
What is the reciprocal of the power factor?
impedance/resistance
How does coil resistance affect angle between the current in a resistor and the current in an inductor?
Coil resistance affects the phase angle between the current in a resistor and the current in an inductor by influencing the total impedance of the circuit. In an inductive circuit, the presence of resistance causes the current to lag behind the voltage, reducing the phase difference. Higher resistance results in a smaller angle, as the resistive component (which is in phase with the voltage) becomes more significant compared to the inductive reactance, which causes the current to lag. Consequently, the angle approaches zero as resistance increases, indicating that the current becomes more aligned with the voltage.
What is the value of resistance ot coil having impedance of 50ohm connected across 240v at 0.8 p.f?
To find the resistance of a coil with an impedance of 50 ohms connected across 240V at a power factor of 0.8, we can use the formula for power factor: ( \text{p.f.} = \frac{R}{Z} ), where ( R ) is the resistance and ( Z ) is the impedance. Rearranging gives ( R = \text{p.f.} \times Z ). Thus, ( R = 0.8 \times 50 , \text{ohms} = 40 , \text{ohms} ). Therefore, the resistance of the coil is 40 ohms.
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.
What current will flow through the heating coil when the heater is plugged in?
The current flowing through the heating coil will depend on the resistance of the coil and the voltage of the power source. Using Ohm's Law (I = V/R), where I is the current, V is the voltage, and R is the resistance, you can calculate the current. The higher the voltage or lower the resistance, the higher the current.
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 a coil of 1ohm resistance is prefered in auxiliary circuit?
A coil with 1 ohm resistance is preferred in auxiliary circuits because it provides a low impedance path, allowing for efficient current flow and minimizing power loss. This low resistance can help protect sensitive components from excessive current while maintaining adequate performance. Additionally, it enables faster response times in controlling devices, which is crucial for reliable operation in auxiliary applications.
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.
Why do the magnetic forces acting on the coil change as the current running through the coil changes?
The magnetic forces acting on the coil change with the current because the strength of the magnetic field produced by the current in the coil is directly proportional to the current flowing through it. As the current changes, the magnetic field strength changes, leading to a change in the magnetic forces acting on the coil.
