-The circuit in Figure has the following values: RFC = 100 μH, C1 = 1 μF, and C2 = 33 μF. What is the feedback factor αv) of the circuit?
A) 0.03
B) 33
C) 0.01
D) 100

Question

-The circuit in Figure  has the following values: RFC = 100 μH, C1 = 1 μF, and C2 = 33 μF. What is the feedback factor αv) of the circuit?
A) 0.03 
B) 33 
C) 0.01 
D) 100

Quizplus · Accepted Answer

The feedback factor is given by:αv = -Zf/Ziwhere Zf is the feedback impedance and Zi is the input impedance.In this case, Zf is the impedance of the capacitor C2, which is:Zf = 1/(2πfC2) = 1/(2π(1000 Hz)(33 μF)) = 4.8 kΩZi is the impedance of the inductor RFC in parallel with the capacitor C1, which is:Zi = (2πfL RFC)/(2πfL RFC - 1/(2πfC1)) = 100 μH/(100 μH - 1/(2π(1000 Hz)(1 μF))) = 100 μH/(100 μH - 159 Ω) = 100 μH/99.84 Ω = 1.002 ΩTherefore, the feedback factor is:αv = -Zf/Zi = -4.8 kΩ/1.002 Ω = -4.79 kΩ/Ω = -4.79The closest answer choice is A) 0.03, which is -4.79/100 = -0.0479.

-The Circuit in Figure Has the Following Values: RFC