Tricky voltage gain negative feedback question

[benji_styler]

Any ideas on how to solve this question?

should gain with feedback be used: A/ 1+AB

Need a little help.


A large quantity of cheap amplifiers are manufactured but they have a wide variation in voltage gain - anything from 500 to 5000. It is proposed to appy the same negative feedback to each amplifier in an attempt to ensure taht all amplifiers have their voltage gain stabilised to within a range of 50 to 55. will it be successful?

 

[Weiming]

I think it will be ok.
If the feedback coefficient is 1/55, and the amplifier's gain is 500 , the amplifier with negative feedback has approximately 50 gain. If the amplifier's gain is 5000 or larger, then the gain of amplifier with feedback will be approximately 55.

thanks.