Calculate capacitance to adjust current in ac circuit

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SUMMARY

The discussion focuses on calculating the required capacitance to adjust the current flow in an AC circuit involving a 100W, 110V lamp powered by a 230V RMS source at 50Hz. The current through the lamp is determined to be 0.909 amps using the formula P=IV. Participants explore the relationship between impedance, resistance, and capacitive reactance, emphasizing the need to separate total impedance into its components to find the necessary capacitance for current adjustment.

PREREQUISITES
  • Understanding of AC circuit fundamentals
  • Familiarity with Ohm's Law (P=IV)
  • Knowledge of capacitive reactance (Xc = 1/(2πfC))
  • Ability to calculate impedance in AC circuits
NEXT STEPS
  • Calculate the required capacitive reactance using the formula Xc = V/I
  • Learn how to separate total impedance into resistance and capacitive reactance
  • Study the relationship between frequency and capacitance in AC circuits
  • Explore practical applications of capacitors in AC circuit design
USEFUL FOR

Electrical engineering students, hobbyists working with AC circuits, and professionals designing circuits requiring current regulation.

krhisjun
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Homework Statement



A Purely resistive resistive 100w, 110v lamp is to be supplied by an a.c. source of 230v r.m.s at 50Hz. what value of pure capacitance could be put in series to adjust the current flow to a suitable value?

Homework Equations


p=iv
q=cv
v=ir
i know a number of other time dependent equations but i don't want to list them all pointlessly

The Attempt at a Solution


Im not sure of how best to approach this, i don't have much experience with AC circuits. i know the current at the lamp is 0.909 amps, from p =iv. but id appreciate a push in the right direction

cheers,khris
 
Physics news on Phys.org
If you were to add a resistor to limit the current instead of a capacitor, could you calculate how much total resistance is needed to limit the current to the correct value?

Do you know how are reactances and resistances added?

Can you do that process in reverse separating the total impedance needed (calculated in the first step) into resistance and capacitive reactance.

Can you calculate capacitance from capacitive reactance and frequency?
 

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