An amplifier without feedback has a voltage gain of 50, input resistance of 1 kΩ & Output resistance of 2.5 kΩ.The input resistance of the current shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 is
A. $$\frac{1}{{11}}{\text{k}}\Omega $$
B. $$\frac{1}{5}{\text{k}}\Omega $$
C. 5 kΩ
D. 11 kΩ
Answer: Option A
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Comments ( 4 )
The action of JFET in its equivalent circuit can best be represented as a
A. Current controlled Current source
B. Current controlled voltage source
C. Voltage controlled voltage source
D. Voltage controlled current source
In a p+n junction diode under reverse bias, the magnitude of electric field is maximum at
A. The edge of the depletion region on the p-side
B. The edge of the depletion region on the n-side
C. The p+n junction
D. The center of the depletion region on the n-side
To prevent a DC return between source and load, it is necessary to use
A. Resistor between source and load
B. Inductor between source and load
C. Capacitor between source and load
D. Either A or B
1/5
R input/ (1+beta. gain)
Ri/(1 + beta.volt gain)
1k ohm/ (1 + 50×0.2)
Could you please explain?