Discussion
A pair has a differential gain of \( 200 \) and a common-mode gain of \( 0.02 \). Its rejection ratio is
Answer: B
Taking the ratio and converting:
\[ \begin{aligned} \text{CMRR} &= \tfrac{200}{0.02} = 10^{4} \\ &= 20\log_{10}10^{4} = 80 \ \mathrm{dB} \end{aligned} \]
giving 80 dB. The value 10000 is the ratio itself rather than its decibel form, and forty decibels would follow from the power convention, which does not apply to a ratio of voltage gains. Establishing whether a quantity is a power or an amplitude before converting is what settles the factor of two. Working one numerical case through both cases side by side fixes the distinction better than any rule of thumb.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development