The voltage gain of an amplifier with 9% negative feedback is 10. The voltage gain without feedback will be:
Answer & explanation
Correct answer: option 2
The voltage gain of the amplifier with negative feedback is
$A'=\frac{A}{1+βA}$
Where, A = voltage gain without feedback
β = feedback factor
Here, A' =10, β = 9% = 0.09
$∴10=\frac{A}{1+0.09A}$
$10 + 0.9 A = A$
$A (1 – 0.9) = 0$
$A=\frac{10}{0.1}=100$