The following were installed in an AC circuit:
An ammeter, which reads 15 $$A_(rms)$$
A voltmeter, which reads 115 $$V_(rms)$$
A wattmeter, which reads 1,500 W
The power factor of the circuit is most nearly:
A. -0.87
B. -0.5
C. 0.5
D. 0.87
The following were installed in an AC circuit:
An ammeter, which reads 15 $$A_(rms)$$
A voltmeter, which reads 115 $$V_(rms)$$
A wattmeter, which reads 1,500 W
The power factor of the circuit is most nearly:
A. -0.87
B. -0.5
C. 0.5
D. 0.87
1 Answer
DEMETRIOS LAMBROPOULOS
Updated on December 24th, 2020Before we can calculate the power factor of the circuit we need to find the apparent power, , of the circuit. The apparent power is a combination of the reactive power and true power of the circuit and is the product of the circuit's voltage and current without reference to the phase angle. The apparent power can be calculated as follows:
Now we can use this to calculate the power factor as follows:
The answer is D. 0.87.
Related Questions
Which of the following are properties of balanced 3-phase power systems? Select all that apply.
A. All 3-phase voltages have equal magnitude and are 90° apart.
B. Three-phase systems transmit alternating currents.
C. Neutral wire, if present, carries no current.
D. Three-phase systems can produce rotating magnetic field.
E. In a wye connection, the line voltage equals the phase voltage.
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