Q. The voltage gain of an amplifier with 9% negative feedback is 10. The voltage gain without feedback will be
A) 100
B) 90
C) 10
D) 1.25
Explanation
[Solution from source] With negative feedback, A_f = A/(1 + βA) with β = 0.09. Then 10 = A/(1 + 0.09A) gives 10 + 0.9A = A, so 0.1A = 10 and A = 100. A gain of 10 without feedback is impossible, because negative feedback always lowers the gain. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.