Ac circuit non inductive resistor and a coil

In summary, the problem is to determine the inductance of a coil that must be connected in series with a non-inductive resistor to supply a load of 8A at 100 volts from a 220 volt 60 Hz mains. The relevant equations are Z^2 = R^2 + XL^2, R=V/I, and XL = 2pi(frequency) L. The solution involves using the voltage divider rule for complex impedance in series with the new voltage of 220 VAC. Any finite inductance will supply the load at the same RMS current.
  • #1
herbgriffin
17
0

Homework Statement


A non inductive resistor takes 8A at 100 volts. What inductance of a coil of negligible resistance must be connected in series in order that this load can be supplied from a 220 volt 60 Hz mains.



Homework Equations


Z^2 = R^2 + XL^2
R=V/I
XL = 2pi(frequency) L(inductance)

The Attempt at a Solution


i have solve the resistance before the coil is added.. R=12.5 ohms...
i am stuck on how to get the value of the coil since there is no given current..
 
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  • #2
(Stipud educators. The correct answer to this question is that any finite inductance will "supply" the load!)

The implied question phrased in more than half-witted manner is, "What will supply the load at the same RMS current?

You know the new voltage. It's 220 VAC. So it's not the same one you used to find R.

Use the voltage divider rule for complex impedance in series. Remember the one for finding the voltage across one resistor that's in series with a second resistor? It looks the same.
 

1. What is an AC circuit non-inductive resistor?

An AC circuit non-inductive resistor is a type of resistor that does not have any inductance, meaning it does not store energy in a magnetic field. This allows it to act purely as a resistance to the flow of alternating current (AC) in a circuit.

2. How does a non-inductive resistor differ from a regular resistor?

A regular resistor has some level of inductance, which can affect the behavior of an AC circuit. A non-inductive resistor, on the other hand, has very low or no inductance, allowing for a more accurate representation of resistance in an AC circuit.

3. What is the purpose of a coil in an AC circuit?

A coil is a type of inductor that is commonly used in AC circuits to store energy in a magnetic field. It can also be used to regulate the flow of current in a circuit.

4. How does a coil affect the behavior of an AC circuit non-inductive resistor?

The presence of a coil in an AC circuit can cause fluctuations in the current and voltage, as well as introduce a phase difference between them. This can affect the overall resistance in the circuit and alter the behavior of a non-inductive resistor.

5. Can a non-inductive resistor and a coil be used together in an AC circuit?

Yes, a non-inductive resistor and a coil can be used together in an AC circuit. However, their combined presence may alter the overall behavior of the circuit, and careful consideration must be taken when designing the circuit to ensure proper functionality.

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