The voltage gain of an amplifier with `9%` negative feedback is `10`. The voltage gain without feedback will be

Options

A. 90
B. 10
C. 1.25
D. 100

Answer

D

Explanation

Here, `A_(fb)=10, A=?, m=9%=9/100`
As `A_(fb)=A/(1+Am) :. 10=A/(1+Axx9/100)`
On solving, `A=100`