A capacitor with a capacitive reactance of 40.0 Ω is connected in series with a 100-Ω resistor across an ac source of frequency 60.0 Hz. What is the phase angle?
A) +68.2°
B) -68.2°
C) -21.8°
D) +21.8°
E) 90.0°

Question

Quizplus · Accepted Answer

The phase angle φ in an R-C circuit is given by φ = arctan(-Xc/R), where Xc is the capacitive reactance and R is the resistance. Here, φ = arctan(-40/100) = arctan(-0.4) ≈ -21.8°.

A Capacitor with a Capacitive Reactance of 40