GATE Electrical – Analog Electronics
Practice Problems – Page 8
This section contains problems based on Differential Amplifier and Common Mode Analysis.
Problem 71
Question:
Define differential amplifier.
Answer:
A differential amplifier amplifies the difference between two input signals.
Problem 72
Question:
Write the formula for differential input voltage.
Answer:
Vd = V1 − V2
Problem 73
Question:
What is common mode input voltage?
Answer:
Vc = (V1 + V2) / 2
Problem 74
Question:
Define CMRR.
Answer:
CMRR (Common Mode Rejection Ratio) is the ratio of differential gain to common mode gain.
CMRR = Ad / Ac
Problem 75
Question:
If differential gain Ad = 200 and common mode gain Ac = 0.5, calculate CMRR.
Solution:
CMRR = Ad / Ac
CMRR = 200 / 0.5
CMRR = 400
Problem 76
Question:
Express CMRR in decibels if CMRR = 400.
Solution:
CMRR(dB) = 20 log10 (CMRR)
CMRR(dB) = 20 log10 (400)
≈ 52 dB
Problem 77
Question:
Why is high CMRR desirable in amplifiers?
Answer:
It rejects noise and interference present in common mode signals.
Problem 78
Question:
Which circuit forms the basic stage of operational amplifier?
Answer:
Differential Amplifier
Problem 79
Question:
What is the ideal value of common mode gain?
Answer:
Zero
Problem 80
Question:
What is the ideal value of CMRR?
Answer:
Infinite
.png)
No comments:
Post a Comment