What is the effect of feedback on input and output impedances?

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    Feedback Impedance
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Feedback significantly alters both input and output impedances in circuits, typically reducing input impedance and increasing output impedance. The final values of these impedances can be determined using specific formulas that incorporate feedback factors. Measuring input impedance requires knowledge of the circuit configuration, while output impedance can be assessed through similar measurement techniques. The discussion also references a formula for voltage gain with feedback, prompting inquiry into whether the gain will increase or decrease when a specific feedback value is applied. For detailed understanding, consulting relevant textbooks is recommended.
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Homework Statement
An amplifier has a voltage gain Av = 1000 , input impedance 1 kΩ and output impedance 500Ω A
fraction βv = 0.1 of the output voltage is fed back in the series in opposition to the input voltage. The
input and output impedance after the feedback are given respectively by the approximate values ?
Relevant Equations
A' = A/(1-βA)
I know that when the feedback is connected, the voltage gain changes by the above formula. But I don't know how to find final values of input and output impedances.
 
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How do input and output impedance change when you apply feedback? Have you studied that point?
 
How would you measure the input impedance (i.e. what information about this circuit do you need to calculate this)? How would you measure the output impedance?
Have you drawn a schematic of this circuit yet?
 
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You have mentioned a formula for the gain A´ with feedback ...when you insert the mentioned value βv = 0.1 , will the gain be larger or smaller than A (without feedback)? What do you expect ?

(By the way: An answer to your question can be found in each relevant textbook...did you already spend some time for searchnig?)
 

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