A 4 mV biopotential enters an amplifier with differential gain 2000. Common-mode input noise is 1000 mV and output noise 200 mV. Find CMRR in dB, nearest integer.
Common-mode gain is output-noise/input-noise=200/1000=0.2. Differential/common gain ratio is 2000/0.2=10000. Hence CMRR=20log₁₀(10000)=80 dB. The signal amplitude is not needed once the differential gain is already supplied.
More Sensors and Signal Conditioning questions
GATE 2023 BM Q55– A thermistor has resistance 1 kΩ at 25°C and 500 Ω at 50°C. Find its temperature…
GATE 2023 BM Q62– A metallic strain gauge has resistance 200 Ω, Young’s modulus 80 GPa and Poisson’s ratio…
GATE 2022 BM Q53– A wire material has linear temperature coefficient x×10⁻⁴ °C⁻¹. Its resistance is 50 Ω at…
GATE 2021 BM Q19– Which displacement sensor is known for high sensitivity and a relatively large measurement…
GATE 2021 BM Q20– Which temperature sensor is used in contact-type digital thermometers for measuring body…
GATE 2020 BM Q30– An endoscope’s distal end is 1 mm from the gastrointestinal wall. Fibre core and cladding…