Answer to Question 6

At a certain frequency, a inductor has a reactance of 20 ohms. It is in series with a resistor of 10 ohms. What is the impedance? What is the phase angle between the resistance and the impedance? 
Z2 = (20 W)2 + (10 W) 2 = 500 W^{2} Z = 22 W cos f = R/Z = 10 W ÷ 22.4 W = 0.446 f = cos1 0.446 = 63o 