Calculate the gain of
a negative feedback amplifier with an internal gain of A = 100 and feedback factor `beta =(1)/(1000)`

Explanation

i) For positive feedback
`A_(f)=(A)/(1-Abeta)=(100)/(1-100xx((1)/(1000)))=(100)/(1-0.1)=(100)/(0.9)=111.1`
ii) For negative feedback, `A_(f)=(A)/(1+Abeta)`
`therefore A_(f)=(100)/(1+100xx((1)/(1000)))=(100)/(1+0.1)=(100)/(1.1)=90.909~~90.91`