An amplifier without feedback has a voltage gain of 50,input resistance os 1 KΩ & Output resistance of 2.5KΩ.The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 is___________?
Correct answer: A. 1/11KΩ
- A. 1/11KΩ
- B. 1/5KΩ
- C. 5KΩ
- D. 11KΩ
Explanation
Current-shunt feedback reduces input resistance by the factor 1 + Aβ. Here 1 + Aβ = 1 + 50(0.2) = 11, so the new input resistance is 1 kΩ/11 = 1/11 kΩ.
Last updated
Practise Electronics and Devices
758 free Electronics and Devices MCQs from Electrical Engineering, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Electrical Engineering questions like this
Electrical Engineering is on 2 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
1 db corresponds to_____________change in power level?
A 1,000 V power supply would use_____________ as a filter capacitor?
A 10 V power supply would use ____________ as filter capacitor?
A 2-transistor class B power amplifier is commonly called ______________ amplifier?
A 25eV electron has a speed of______________?