Subelement B: Electrical Math— Topic 13: Power Relationships
Question 3-13B6
Element 3 (GROL)What does the power factor equal in an R-L circuit having a 30 degree phase angle between the voltage and the current?
Explanation
In an AC circuit, the power factor is defined as the cosine of the phase angle (θ) between the voltage and the current. It represents the ratio of true power (or real power) to apparent power.
Given a phase angle of 30 degrees:
Power Factor (PF) = cos(θ)
PF = cos(30°)
The value of cos(30°) is approximately 0.866.
Therefore, the power factor in this R-L circuit is 0.866.
* **A) 1.73:** This is √3, not a cosine value for 30 degrees.
* **C) 0.5:** This would be the power factor for a 60-degree phase angle (cos(60°)).
* **D) 0.577:** This is approximately tan(30°) or 1/√3.
Related Questions
3-13B4 In a circuit where the AC voltage and current are out of phase, how can the true power be determined?3-13B5 What does the power factor equal in an R-L circuit having a 45 degree phase angle between the voltage and the current?3-14B1 What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the supply voltage?3-14B2 What is the meaning of the term “time constant of an RC circuit”? The time required to charge the capacitor in the circuit to:3-14B3 What is the term for the time required for the current in an RL circuit to build up to 63.2% of the maximum value?