Electronics and Communication Engineering - Analog Electronics - Discussion
Discussion Forum : Analog Electronics - Section 1 (Q.No. 10)
10.
If an amplifier with gain of - 1000 and feedback factor β = - 0.1 had a gain change of 20% due to temperature, the change in gain of the feedback amplifier would be
Answer: Option
Explanation:
As we know, Gain with feedback
A = - 1000, β = -0.1 .
Discussion:
25 comments Page 2 of 3.
Siri said:
8 years ago
Thank you @Arnab.
Afsana said:
8 years ago
Thanks @Arnab.
Shri said:
8 years ago
Thank you @Arnab.
Vikas dev negi said:
8 years ago
Thanks @Arnab.
Reshma said:
8 years ago
Now it's clear, thanks @Arnab.
Goki said:
9 years ago
@Arnab.
Thanks for the clear explanation.
Thanks for the clear explanation.
Pavi said:
9 years ago
@Arnab Bhattacharya,
Thanks for the clear explanation.
Thanks for the clear explanation.
Jagadish said:
9 years ago
Lucid Explanation @Arnab.
Kiran said:
9 years ago
Great explanation @Arnab Bhattacharya.
Arnab Bhattacharya said:
10 years ago
This is basically a problem relating the stability of gain of feedback amplifiers.
Given, A = -1000, B (beta) = -0.1; 1+AB = 101.
Now, given, change in amplifier gain = 20%.
We have, (dAf/Af) = (1/(1+AB))*(dA/A).
Here, dA/A = 20% = 0.2; have to find dAf/Af.
Therefore, dAf/Af = (1/101)*0.2 = 0.00198 = 0.198% = 0.2%.
Option (C) is correct. Here it is noticeable how feedback improves the stability in amplifiers. When the deviation of gain in amplifier is 20%, the distortion in the overall (feedback) amplifier circuit is only 0.2%.
Thank you.
Given, A = -1000, B (beta) = -0.1; 1+AB = 101.
Now, given, change in amplifier gain = 20%.
We have, (dAf/Af) = (1/(1+AB))*(dA/A).
Here, dA/A = 20% = 0.2; have to find dAf/Af.
Therefore, dAf/Af = (1/101)*0.2 = 0.00198 = 0.198% = 0.2%.
Option (C) is correct. Here it is noticeable how feedback improves the stability in amplifiers. When the deviation of gain in amplifier is 20%, the distortion in the overall (feedback) amplifier circuit is only 0.2%.
Thank you.
(1)
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