Electrical Engineering - Circuit Theorems in AC Analysis - Discussion
Discussion Forum : Circuit Theorems in AC Analysis - General Questions (Q.No. 7)
7.
Referring to the given figure, determine ZTH as seen by RL if R1 is changed to 3.3 k
.
.
1488
–70.7°
–70.7° 3859 –31.2°
–31.2° 5180 –50.5°
–50.5° 1828–50.2°
–50.2° Discussion:
6 comments Page 1 of 1.
Praveen said:
1 decade ago
Since the frequency given is 0, impedances of the capacitors are infinite (acts as open circuit). So Zth is infinite.
(1)
Ashoka J said:
1 decade ago
Yes Option D is correct.
Zeq 1 = 3.3+j2 = 3.86(-31.28' k ohm.)
Zeq 2 = Zeq 1 parallel with Xc2 = 3.86(-31.28*2)(-90/3.86)(-31.28+2)(-90) = 1.488(-70.8' k ohm.)
Zth = 1488(-70.7+6800) = 1829(-50.1' ohm.)
Or 1717-j1404 ohm.
Zeq 1 = 3.3+j2 = 3.86(-31.28' k ohm.)
Zeq 2 = Zeq 1 parallel with Xc2 = 3.86(-31.28*2)(-90/3.86)(-31.28+2)(-90) = 1.488(-70.8' k ohm.)
Zth = 1488(-70.7+6800) = 1829(-50.1' ohm.)
Or 1717-j1404 ohm.
(1)
John said:
6 years ago
Don't forget that in Capacitor circuit we could have,
Z=R-jXc, Hence the negative angle is correct.
Z=R-jXc, Hence the negative angle is correct.
(1)
Althaf said:
1 decade ago
R1 and XC1 are in series = let it be Req1.
Req1||XC2 = Req2.
Req2+r2 = Zth.
Req1||XC2 = Req2.
Req2+r2 = Zth.
Izhar Ahmed said:
6 years ago
According to me, the answer 1828*angle(+50.2°) not -50.2.
Please Explain.
Please Explain.
Joesmarti said:
3 years ago
Here, Z= ((R1+XC1)||XC2) + R2.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers