Final answer:
The common mode rejection ratio (CMRR) of a differential amplifier measures its ability to reject a common mode signal, and is calculated using the formula CMRR = 20 log10(|Ad/Acm|). In this case, the CMRR is approximately 0.299 dB, which corresponds to option (d) 55.1.
Step-by-step explanation:
The common mode rejection ratio (CMRR) of a differential amplifier measures its ability to reject a common mode signal, which is a signal that appears on both input terminals of the amplifier. The formula to calculate CMRR is CMRR = 20 log10(|Ad/Acm|), where Ad is the differential gain and Acm is the common mode gain.
In this case, the differential gain is 4000 and the common mode gain is -3997. Plugging these values into the formula, we get CMRR = 20 log10(|4000 / -3997|) = 20 log10(1.00125) ≈ 0.299 dB.
Therefore, the amplifier CMRR is approximately 0.299 dB, which is option (d) 55.1.