7.7 - POWER IN A CIRCUIT: THE POWER FACTOR
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Practice Questions
Test your understanding with targeted questions
What is the formula for calculating power factor?
💡 Hint: Think about the phase relationship between current and voltage.
What happens to power factor in a purely resistive circuit?
💡 Hint: Is there a phase difference in a resistive circuit?
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Interactive Quizzes
Quick quizzes to reinforce your learning
What does a power factor of 0 indicate in a circuit?
💡 Hint: Consider what happens when currents and voltages are 90 degrees out of phase.
True or False: At resonance, power factor is always 0.
💡 Hint: Think about what resonance means in terms of power transfer.
1 more question available
Challenge Problems
Push your limits with advanced challenges
In an LCR series circuit with R = 50 Ω, L = 200 mH, and C = 100 μF, find the resonant frequency and the average power for a supplied RMS voltage of 240V.
💡 Hint: First, solve for the reactances, then adjust for resonance.
Calculate the power factor and average power for an AC circuit where the voltage is 400 V RMS, current is 12 A RMS, and the phase angle is 30 degrees.
💡 Hint: Use trigonometric identities to assist in determining the power factor.
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