In the circuit shown below, XL = 80 ohms and XC = 60 ohms with the circuit opera
ID: 1934387 • Letter: I
Question
In the circuit shown below, XL = 80 ohms and XC = 60 ohms with the circuit operating at f = 663 Hz
A.)Calculate the value of the combined impedance, ZT(do not includephase angle here): ___ohms
B.)Calculate the phase angle of the combined impedance, ZT(do not include value of impedance here, just its angle): ____degrees
C.)Given this circuit's total impedance, calculated earlier, this inductor and capacitor pair can be replaced with just one single componentat the stated frequency. What is that component, and what is its value?
Select One:
a.) An inductor of 58 mH
b.) A capacitor of 1.0 uF
c.) An inductor of 240 mH
d.) A capacitor of 0.25 uF
e.) A capactior of 240 uF
f.) None of the above
Explanation / Answer
ZT = j80(-j60) / (j80 - j60)
ZT = 4800 / j20 = -j 240
hence ZT = 240 < -90o
so,
A) ZT = 240
B) angle = -90 or 270 degrees
C) ZT = -j 240 = -j / (2fC)
=> 240 = 1 / (2fC)
=> C = 1/ (2f x 240) = 1 F (option b)