What Is the Correct Formula for Calculating Average Power in an AC Circuit?

Click For Summary
SUMMARY

The correct formula for calculating average power in an AC circuit is P(avg) = I(avg) * V(avg), not P(avg) = I(avg) * V(max). In the discussion, the user attempted to calculate average power using the maximum voltage and the root mean square (RMS) current derived from I(max) = 0.191 A. The resistance of the circuit is 68 ohms, and the maximum voltage is 22.5 volts. The user’s initial approach was incorrect due to the use of maximum voltage instead of average voltage.

PREREQUISITES
  • Understanding of AC circuit fundamentals
  • Knowledge of RMS current calculation
  • Familiarity with voltage types (maximum vs. average)
  • Basic electrical engineering principles
NEXT STEPS
  • Study the derivation of average power formulas in AC circuits
  • Learn about RMS voltage and current calculations
  • Explore the differences between maximum and average voltage in AC systems
  • Review Ohm's Law and its application in AC circuits
USEFUL FOR

Electrical engineering students, educators teaching AC circuit theory, and professionals involved in circuit design and analysis.

Tekee
Messages
20
Reaction score
0

Homework Statement



Given resistance of circuit 68 W, I(max) = .191 A, V(max) = 22.5, what is the average power of this circuit?

Homework Equations



P(avg) = I(avg)V(max)

The Attempt at a Solution



I took .191 and divided by sqrt(2) to get the rms current and multiplied by the max voltage 22.5. Not getting the right answer, though...
 
Physics news on Phys.org
P(avg) = I(avg)V(max)
It should be
P(avg) = I(avg)V(avg)
 

Similar threads

Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
1
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 3 ·
Replies
3
Views
4K