Consider an ac power supply which operates at a frequency of f = 60 Hz and suppl

ID: 1541071 • Letter: C

Question

Consider an ac power supply which operates at a frequency of f = 60 Hz and supplies a maximum voltage of Vmax = 17 V.

(a) Initially, a capacitor with capacitance C = 5.0 F is connected to the power supply.

i. What is the reactance of the capacitor?

ii. What is the maximum current?

iii. Does the current lead or lag behind the voltage?

(b) The capacitor is then disconnected from the power supply and replaced with an inductor with an inductance of L = 15 mH.

i. What is the reactance of the inductor?

ii. What is the maximum current?
iii. Does the current lead or lag behind the voltage?

part(a)

(i)reactance Xc = 1/(wc) = 1/2*pi*f*C = 1/(2*pi*60*5*10^-6) = 530.5 ohms

(ii) current i = Vmax/Xc = 17/530.5 = 0.032 A

(iii) lag behind the votage

part(b)

(i)reactance XL = (wL) = 2*pi*f*L = (2*pi*60*15*10^-3) = 5.65 ohms

(ii) current i = Vmax/Xc = 17/5.65 = 3 A

(iii) lead the voltage