Question

Question #03d44

Answer 1

The answer is selection: a) 5

Explanation:

The general equation for a positive feedback system is:

`A_"c" = A_"ol"/(1 - betaA_"ol")" [1]"`

Where `A_"c"` is the closed loop gain, `A_"ol"` is open loop gain, and, `beta` is the gain of the feedback circuit.

We are given that `A_"c" = 10`

And the phrase; "10% positive feedback" implies that `beta = 0.1`

Substitute these values into equation [1] and solve for `A_"ol"`:

`10 = A_"ol"/(1- 0.1A_"ol")`

`10(1- 0.1A_"ol") = A_"ol"`

`10- A_"ol" = A_"ol"`

`2A_"ol"=10`

`A_"ol" = 5`

The answer is selection: a) 5