Ac circuit non inductive resistor and a coil

Click For Summary
SUMMARY

The discussion centers on calculating the required inductance of a coil that must be connected in series with a non-inductive resistor, which draws 8A at 100 volts, to operate from a 220V, 60Hz mains supply. The resistance of the non-inductive resistor is determined to be 12.5 ohms. The key equation used is the impedance formula Z² = R² + XL², where XL represents the inductive reactance calculated as XL = 2πfL. The conclusion emphasizes that any finite inductance will suffice to supply the load at the same RMS current.

PREREQUISITES
  • Understanding of AC circuit analysis
  • Familiarity with Ohm's Law (R = V/I)
  • Knowledge of impedance in series circuits
  • Basic understanding of inductive reactance (XL = 2πfL)
NEXT STEPS
  • Study the voltage divider rule for complex impedance in series circuits
  • Learn about the impact of inductance on AC circuit behavior
  • Explore the concept of RMS current in AC circuits
  • Investigate practical applications of non-inductive resistors in electrical engineering
USEFUL FOR

Electrical engineering students, circuit designers, and anyone involved in AC circuit analysis and design will benefit from this discussion.

herbgriffin
Messages
17
Reaction score
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..
 
Physics news on Phys.org
(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.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
8K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 26 ·
Replies
26
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
Replies
15
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
2
Views
2K
Replies
5
Views
3K