This document provides information about calculating power factor from a given circuit. It states that the input voltage is 120 cos(377t - 45°) Vrms and the current is 7 cos(377t - 10°) Arms. It asks to: 1) Calculate the power factor of the circuit by taking the cosine of the phase difference between the voltage and current. 2) Determine if the power factor is lagging or leading.

1. 10.0 Points Question 8 of 8 Accepted characters: numbers, decimal point markers (period or
comma sign indicators spaces (e.g., as thousands separator, 5 000 "E" or "e" (used in scientific
notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a bi here "a" and "b" need to have explicitly stated
values. For example: 1+1 is valid whereas (1+i s not. 10+9i is valid whereas (9i is not. Q8f No
figure A circuit has the following input voltage with the resulting current v 120 cos (377t 45°)
Vrms i 7 cos (377t 10°) Arms a) Find the power factor of this circuit. pf b) Is this a lagging or
leading power factor? 1 Lagging power factor 2 Leading power factor
Solution
Ans A) Power factor is Cos[phase difference in V and I]
Power factor = Cos(55) = 0.573
Ans B) Power factor is leading because current leading the voltage