Q.1 What does the abbreviation ECG stand for?
Electrocardiograph
Electrocardiogram
Electronic Cardiograph
Echocardiogram
Explanation - ECG is short for Electrocardiogram, the test that records the electrical activity of the heart.
Correct answer is: Electrocardiogram
Q.2 Which component of a pulse oximeter measures light absorption?
Transmitter
Receiver
LED
Microcontroller
Explanation - The LED emits light that passes through tissue; the receiver detects the light that is transmitted.
Correct answer is: LED
Q.3 Which range of frequencies is typically used for recording an electroencephalogram (EEG)?
0.5–30 Hz
30–100 Hz
100–200 Hz
200–500 Hz
Explanation - EEG signals are usually within 0.5–30 Hz to capture the brain's electrical activity.
Correct answer is: 0.5–30 Hz
Q.4 What is the main purpose of an amplifier in an ECG circuit?
To increase signal amplitude
To filter out noise
To convert AC to DC
To provide power supply
Explanation - ECG signals are microvolt-level; an amplifier boosts their amplitude for further processing.
Correct answer is: To increase signal amplitude
Q.5 Which sensor is used in a blood pressure cuff to measure arterial pressure?
Pressure transducer
Thermocouple
Piezoelectric sensor
Accelerometer
Explanation - The pressure transducer converts the cuff pressure into an electrical signal.
Correct answer is: Pressure transducer
Q.6 Which of the following is NOT a typical feature of a biomedical instrument’s user interface?
Touchscreen display
Audible alerts
LED status indicators
Mechanical keyboard
Explanation - Biomedical instruments usually have touchscreens or simple buttons, not mechanical keyboards.
Correct answer is: Mechanical keyboard
Q.7 What type of filter would remove high-frequency noise from a biomedical signal?
Low-pass filter
High-pass filter
Band-pass filter
Notch filter
Explanation - A low‑pass filter allows low-frequency components to pass while attenuating high-frequency noise.
Correct answer is: Low-pass filter
Q.8 Which device is used to record muscle electrical activity?
EMG sensor
ECG sensor
EEG sensor
PPG sensor
Explanation - EMG (electromyography) records electrical activity generated by skeletal muscles.
Correct answer is: EMG sensor
Q.9 In a photoplethysmogram (PPG) sensor, what is the main source of light?
LED
Laser
Incandescent bulb
UV lamp
Explanation - PPG sensors typically use LEDs to emit light that is then measured by a photodiode.
Correct answer is: LED
Q.10 What is the primary unit of measurement for impedance in biomedical instrumentation?
Ohm
Farad
Henry
Tesla
Explanation - Impedance is measured in ohms, representing resistance to AC flow.
Correct answer is: Ohm
Q.11 Which of the following is a common source of motion artifact in ECG recordings?
Battery depletion
Patient movement
Software glitch
Ambient temperature
Explanation - Motion artifacts arise when electrodes shift or skin contact changes during patient movement.
Correct answer is: Patient movement
Q.12 Which of these is a characteristic of a biopotential signal?
High amplitude (mV range)
Low amplitude (microvolt range)
Direct current (DC) only
Noisy signal
Explanation - Biopotential signals, such as ECG or EEG, typically have microvolt-level amplitudes.
Correct answer is: Low amplitude (microvolt range)
Q.13 What does the Nyquist theorem help determine in biomedical signal acquisition?
Sampling frequency
Filter cutoff
Amplifier gain
Power consumption
Explanation - Nyquist theorem states the sampling rate must be at least twice the highest frequency component.
Correct answer is: Sampling frequency
Q.14 Which sensor type is used in a wearable heart rate monitor?
Photodiode
Accelerometer
Thermistor
Pressure sensor
Explanation - Wearable heart rate monitors typically use optical sensors with LEDs and photodiodes.
Correct answer is: Photodiode
Q.15 In an ECG lead configuration, the baseline drift is often caused by:
Skin–electrode impedance changes
Muscle noise
High‑frequency interference
Battery voltage drop
Explanation - Baseline drift occurs when impedance changes between skin and electrodes.
Correct answer is: Skin–electrode impedance changes
Q.16 Which component converts the analog voltage from a sensor into a digital number in a biomedical device?
Oscilloscope
ADC (Analog‑to‑Digital Converter)
DAC (Digital‑to‑Analog Converter)
Amplifier
Explanation - An ADC samples and quantizes the analog signal for digital processing.
Correct answer is: ADC (Analog‑to‑Digital Converter)
Q.17 What is the main purpose of shielding in biomedical instrumentation?
To reduce electrical noise
To increase power consumption
To provide structural support
To improve signal amplitude
Explanation - Shielding protects sensitive signals from electromagnetic interference.
Correct answer is: To reduce electrical noise
Q.18 Which parameter is NOT measured by a typical pulse oximeter?
SpO2
Heart rate
Blood pressure
Respiratory rate
Explanation - Pulse oximeters measure oxygen saturation and pulse rate; they do not measure blood pressure.
Correct answer is: Blood pressure
Q.19 Which of these is a common artifact in EEG recordings?
Eye blinks
Foot tapping
Skin conductance
All of the above
Explanation - Eye blinks, foot tapping, and skin conductance can all produce artifacts in EEG signals.
Correct answer is: All of the above
Q.20 Which of the following is a non‑invasive imaging modality used in biomedical instrumentation?
CT scan
MRI
Ultrasound
All of the above
Explanation - CT, MRI, and ultrasound are all non‑invasive imaging technologies.
Correct answer is: All of the above
Q.21 What is the typical bandwidth of a biomedical amplifier for ECG signals?
0.05–150 Hz
1–10 kHz
10–100 kHz
50–200 MHz
Explanation - ECG amplifiers typically have a bandwidth that covers the useful frequency range of the ECG.
Correct answer is: 0.05–150 Hz
Q.22 Which of the following best describes a biosensor?
A device that measures temperature only
A device that detects a biological analyte and produces a measurable signal
A mechanical device that counts heartbeats
A chemical reactor
Explanation - Biosensors combine a biological element with a transducer to generate a detectable signal.
Correct answer is: A device that detects a biological analyte and produces a measurable signal
Q.23 In which type of ECG lead configuration is the reference electrode placed on the left leg?
Lead II
Lead V1
Lead aVR
Lead V6
Explanation - In augmented limb lead aVR, the left leg is the reference electrode.
Correct answer is: Lead aVR
Q.24 Which component provides a stable reference voltage in an analog front‑end circuit?
Voltage regulator
Zener diode
Resistor ladder
Capacitor bank
Explanation - A Zener diode can be used to maintain a stable reference voltage in precision circuits.
Correct answer is: Zener diode
Q.25 Which of the following is a key advantage of using a differential amplifier in ECG circuits?
It increases the signal amplitude
It reduces common‑mode noise
It reduces power consumption
It provides a digital output
Explanation - Differential amplifiers cancel common‑mode signals, improving the signal‑to‑noise ratio.
Correct answer is: It reduces common‑mode noise
Q.26 What is the purpose of a notch filter in biomedical signal processing?
To remove 50/60 Hz mains interference
To amplify low‑frequency components
To detect heart beats
To convert AC to DC
Explanation - Notch filters specifically target the power‑line frequency to reduce its impact on the signal.
Correct answer is: To remove 50/60 Hz mains interference
Q.27 Which of these signals is typically sampled at a higher rate than an ECG?
EEG
EMG
PPG
Blood pressure
Explanation - EMG signals contain higher frequency content and thus require a higher sampling rate.
Correct answer is: EMG
Q.28 Which of the following is a common cause of electrode detachment in wearable biosensors?
Sweat evaporation
Skin irritation
Loose cable
All of the above
Explanation - All factors can lead to poor electrode–skin contact and signal loss.
Correct answer is: All of the above
Q.29 In a blood pressure cuff, the inflation of the cuff occludes the artery. Which phenomenon is measured during deflation to determine systolic pressure?
Krebs' pulse
Korotkoff sound
Myoelectric signal
Pulse wave velocity
Explanation - Korotkoff sounds are heard as the cuff deflates; the first sound indicates systolic pressure.
Correct answer is: Korotkoff sound
Q.30 What is the function of an integrator in a biomedical instrumentation circuit?
To compute the derivative of the input signal
To accumulate the input signal over time
To filter high-frequency noise
To provide a digital interface
Explanation - An integrator sums the input signal, which is useful for measuring cumulative quantities.
Correct answer is: To accumulate the input signal over time
Q.31 Which of the following is NOT a typical safety standard for medical electrical equipment?
IEC 60601
ISO 14971
ISO 9001
IEC 62304
Explanation - ISO 9001 is a quality management standard; it does not specifically address medical electrical safety.
Correct answer is: ISO 9001
Q.32 Which type of transducer converts a pressure change into an electrical signal in a blood pressure cuff?
Piezoresistive sensor
Capacitive sensor
Thermistor
Photoelectric sensor
Explanation - Piezoresistive transducers change resistance with pressure, producing a voltage change.
Correct answer is: Piezoresistive sensor
Q.33 What does the term “biopotential” refer to in biomedical instrumentation?
Electrical potentials generated by biological tissues
Chemical potential energy in cells
Thermal potential in body fluids
Mechanical potential energy
Explanation - Biopotentials are electrical signals produced by living tissues, e.g., ECG, EEG.
Correct answer is: Electrical potentials generated by biological tissues
Q.34 Which of the following is a typical sampling rate for a portable ECG monitor?
250 Hz
1 kHz
10 kHz
100 kHz
Explanation - Portable ECG devices often sample at 250–500 Hz to capture relevant cardiac information.
Correct answer is: 250 Hz
Q.35 Why are low‑frequency filters commonly used in ECG circuits?
To remove motion artifacts
To reduce high‑frequency noise
To amplify the ECG signal
To increase battery life
Explanation - Low‑frequency filters help eliminate baseline wander caused by motion.
Correct answer is: To remove motion artifacts
Q.36 Which of the following is an example of a non‑invasive sensor in biomedical instrumentation?
Invasive glucose monitor
MRI scanner
Subcutaneous electrode
Intracranial EEG probe
Explanation - MRI provides imaging without penetrating the body, making it non‑invasive.
Correct answer is: MRI scanner
Q.37 In an ECG signal, the QRS complex is primarily composed of:
Electrical activity of atrial depolarization
Electrical activity of ventricular depolarization
Electrical activity of repolarization
Electrical activity of sympathetic nervous system
Explanation - The QRS complex reflects the rapid depolarization of the ventricles.
Correct answer is: Electrical activity of ventricular depolarization
Q.38 Which of these devices can be used to measure respiratory rate non‑invasively?
Spirometer
Pulse oximeter
Blood glucose monitor
Thermometer
Explanation - Modern pulse oximeters can estimate respiratory rate from photoplethysmographic waveforms.
Correct answer is: Pulse oximeter
Q.39 What does the term “bandwidth” refer to in the context of an instrumentation amplifier?
The range of frequencies over which the amplifier operates effectively
The maximum output voltage
The input impedance
The physical size of the amplifier
Explanation - Bandwidth defines how wide a frequency range the amplifier can process without distortion.
Correct answer is: The range of frequencies over which the amplifier operates effectively
Q.40 Which component is responsible for providing power to a wearable ECG monitor?
Battery pack
Solar panel
Fuel cell
Thermal generator
Explanation - Wearable devices typically use compact batteries as their primary power source.
Correct answer is: Battery pack
Q.41 What is the main purpose of an anti‑aliasing filter in a biomedical data acquisition system?
To increase sampling rate
To prevent high‑frequency components from folding into lower frequencies
To amplify the signal
To convert analog to digital
Explanation - Anti‑aliasing filters limit bandwidth to prevent aliasing during digitization.
Correct answer is: To prevent high‑frequency components from folding into lower frequencies
Q.42 Which of the following is a typical output format for an ECG waveform display?
Graphical plot of voltage vs. time
Textual report
Audio recording
3‑D model
Explanation - ECG displays usually show voltage on the y‑axis and time on the x‑axis.
Correct answer is: Graphical plot of voltage vs. time
Q.43 In a typical biomedical sensor system, the term “sensitivity” refers to:
The minimum detectable signal
The bandwidth of the sensor
The sensor's physical size
The temperature coefficient
Explanation - Sensitivity indicates how small a change in the physical quantity can be measured.
Correct answer is: The minimum detectable signal
Q.44 Which type of sensor is commonly used to detect oxygen saturation in a finger?
Photodiode
Accelerometer
Thermocouple
Microphone
Explanation - Photodiodes detect the light transmitted through tissue to estimate SpO2.
Correct answer is: Photodiode
Q.45 Which of the following is NOT a typical biomedical instrumentation device?
Electroencephalogram (EEG)
Magnetic Resonance Imaging (MRI)
Laser cutting machine
Portable blood pressure monitor
Explanation - Laser cutting machines are industrial tools, not biomedical instrumentation.
Correct answer is: Laser cutting machine
Q.46 The term 'impedance matching' in biomedical circuits is important to:
Maximize power transfer
Minimize signal loss
Reduce noise
All of the above
Explanation - Impedance matching improves signal integrity and reduces reflections.
Correct answer is: All of the above
Q.47 In the context of biomedical instrumentation, what does the acronym 'IC' stand for?
Integrated Circuit
Inertial Control
Internal Capacitor
Input Current
Explanation - ICs are miniaturized electronic components used in many biomedical devices.
Correct answer is: Integrated Circuit
Q.48 Which of the following is a characteristic of a high‑pass filter?
It attenuates low‑frequency signals
It amplifies high‑frequency signals
It blocks high‑frequency signals
It blocks low‑frequency signals only when the input is zero
Explanation - High‑pass filters allow high‑frequency components to pass while attenuating low‑frequency ones.
Correct answer is: It attenuates low‑frequency signals
Q.49 What is the main difference between a wired and wireless biomedical sensor?
Power consumption
Signal quality
Data transfer method
Battery size
Explanation - Wireless sensors transmit data via radio frequency, whereas wired sensors use cables.
Correct answer is: Data transfer method
Q.50 Which of these is an example of a digital health device?
Digital blood pressure cuff
Analog ECG lead
Mechanical heart monitor
Paper ECG sheet
Explanation - Digital cuffs display readings digitally and may store data for analysis.
Correct answer is: Digital blood pressure cuff
Q.51 What is the typical maximum operating temperature for a biomedical implant?
37 °C
40 °C
50 °C
60 °C
Explanation - Implants must not exceed body temperature; 40 °C is a common safety limit.
Correct answer is: 40 °C
Q.52 Which type of biomedical sensor uses the piezoelectric effect to detect pressure changes?
Piezoelectric transducer
Photodiode
Capacitive pressure sensor
Thermistor
Explanation - Piezoelectric materials generate voltage when mechanically stressed, useful for pressure sensing.
Correct answer is: Piezoelectric transducer
Q.53 In a typical ECG monitor, which lead placement records the electrical activity of the left arm?
Lead I
Lead II
Lead III
Lead aVR
Explanation - Lead aVR uses the left arm as the positive electrode with a reference on the right leg.
Correct answer is: Lead aVR
Q.54 The term 'sampling jitter' refers to:
Variability in sampling time intervals
Noise introduced by the amplifier
Delay in signal transmission
High‑frequency noise
Explanation - Jitter is the variation from the expected sampling clock period.
Correct answer is: Variability in sampling time intervals
Q.55 Which of the following is an example of an invasive biomedical measurement?
Blood glucose fingerstick
ECG with skin electrodes
Pulse oximetry
EEG with scalp electrodes
Explanation - A fingerstick requires puncturing the skin, making it invasive.
Correct answer is: Blood glucose fingerstick
Q.56 In a typical pulse oximeter, which wavelength of light is used to calculate SpO2?
Red (660 nm) and Infrared (940 nm)
Green (520 nm) only
Blue (450 nm) only
Ultraviolet (310 nm) only
Explanation - SpO2 is derived from the ratio of red to infrared absorption.
Correct answer is: Red (660 nm) and Infrared (940 nm)
Q.57 The term 'biocompatibility' in biomedical instrumentation refers to:
The device's ability to function in the human body
The device's electrical safety
The device's mechanical strength
The device's software reliability
Explanation - Biocompatibility ensures materials do not provoke harmful biological responses.
Correct answer is: The device's ability to function in the human body
Q.58 What is the main advantage of using a low‑noise pre‑amplifier in an EEG system?
Higher battery life
Improved signal‑to‑noise ratio
Lower cost
Smaller size
Explanation - A low‑noise pre‑amplifier preserves the tiny EEG signals against background noise.
Correct answer is: Improved signal‑to‑noise ratio
Q.59 Which type of biomedical instrument is commonly used for measuring insulin levels?
Glucose meter
Insulin pump
Insulin sensor
Blood pressure cuff
Explanation - Insulin sensors measure insulin concentration for diabetes management.
Correct answer is: Insulin sensor
Q.60 The term 'ADC resolution' refers to:
The number of bits used to represent a digital value
The analog input range
The conversion time
The power consumption
Explanation - Higher resolution allows finer discrimination of small voltage differences.
Correct answer is: The number of bits used to represent a digital value
Q.61 Which of the following best describes a 'band‑stop' filter?
It blocks a specific frequency band
It passes all frequencies
It amplifies a band of frequencies
It reduces the entire signal amplitude
Explanation - A band‑stop filter removes frequencies within a defined range while leaving others unaffected.
Correct answer is: It blocks a specific frequency band
Q.62 Which of these is an example of a physiological parameter that can be measured non‑invasively?
Blood glucose
Blood pressure
Body temperature
Heart rate
Explanation - Heart rate can be measured via ECG or pulse oximetry without invasive procedures.
Correct answer is: Heart rate
Q.63 Why is electrode impedance important in an ECG measurement?
It affects signal amplitude
It determines battery life
It controls the sampling rate
It sets the display resolution
Explanation - High electrode impedance reduces signal transfer, lowering amplitude and quality.
Correct answer is: It affects signal amplitude
Q.64 Which type of sensor is commonly used for measuring body temperature?
Thermocouple
Thermistor
Photodiode
Accelerometer
Explanation - Thermistors change resistance with temperature, making them suitable for body temperature measurement.
Correct answer is: Thermistor
Q.65 In a biomedical instrument, the 'safety factor' is used to:
Ensure devices operate below hazardous limits
Improve signal quality
Reduce cost
Speed up data processing
Explanation - The safety factor provides a margin to avoid exceeding safe operating parameters.
Correct answer is: Ensure devices operate below hazardous limits
Q.66 Which of the following is a common type of electrode used in EEG recordings?
Ag/AgCl
Gold‑plated
Silicon
Aluminum
Explanation - Ag/AgCl electrodes provide low noise and stable impedance for EEG.
Correct answer is: Ag/AgCl
Q.67 What does 'common‑mode rejection ratio' (CMRR) indicate in a differential amplifier?
Its ability to reject common signals
Its bandwidth
Its power consumption
Its input impedance
Explanation - CMRR quantifies how well the amplifier rejects signals common to both inputs.
Correct answer is: Its ability to reject common signals
Q.68 Which of the following best describes a 'real‑time' biomedical system?
Processes data as it is acquired
Processes data after acquisition
Stores data for later analysis
Uses only analog signals
Explanation - Real‑time systems provide immediate feedback or monitoring.
Correct answer is: Processes data as it is acquired
Q.69 Which component in a pulse oximeter helps to convert the detected optical signal into an electrical one?
Photodiode
LED driver
Microcontroller
Power supply
Explanation - The photodiode generates a current proportional to the received light intensity.
Correct answer is: Photodiode
Q.70 A biomedical instrument that converts a chemical reaction into a measurable electrical signal is known as:
Chemical biosensor
Optical sensor
Mechanical sensor
Thermal sensor
Explanation - Chemical biosensors detect analytes via specific chemical reactions producing an electrical output.
Correct answer is: Chemical biosensor
Q.71 In ECG lead placement, the right arm electrode is typically referred to as:
RA
LA
RL
RA
Explanation - RA stands for Right Arm, commonly used as an electrode site.
Correct answer is: RA
Q.72 Which of the following is a key feature of a low‑power wearable medical device?
High battery consumption
Long battery life
Large form factor
Frequent calibration
Explanation - Wearables aim to operate for extended periods with minimal charging.
Correct answer is: Long battery life
Q.73 Which sensor technology is typically used in a wearable motion tracker?
Accelerometer
Photodiode
Thermistor
Pressure sensor
Explanation - Accelerometers measure acceleration to detect motion or posture changes.
Correct answer is: Accelerometer
Q.74 The process of converting a chemical analyte into an electrical signal in a biosensor is called:
Transduction
Amplification
Digitization
Calibration
Explanation - Transduction is the conversion of one form of energy (chemical) into another (electrical).
Correct answer is: Transduction
Q.75 Which of the following best describes a 'passive' biomedical sensor?
It requires external power to operate
It operates without any external power source
It is only used in laboratory settings
It only measures temperature
Explanation - Passive sensors do not have internal power and rely on external stimuli.
Correct answer is: It operates without any external power source
Q.76 Which parameter is typically displayed by a digital blood glucose monitor?
Glucose concentration in mg/dL
Heart rate in bpm
SpO2 percentage
Blood pressure in mmHg
Explanation - The monitor directly reads glucose levels, typically expressed in mg/dL.
Correct answer is: Glucose concentration in mg/dL
Q.77 In a biomedical instrument, the term 'noise figure' refers to:
The amount of noise added by the amplifier
The bandwidth of the signal
The input voltage range
The output signal amplitude
Explanation - Noise figure quantifies how much noise an amplifier contributes to the signal.
Correct answer is: The amount of noise added by the amplifier
Q.78 Which type of electrode is commonly used for ECG in ambulatory monitoring?
Disposable gel electrodes
Intracranial electrodes
Skin‑contact electrodes with adhesives
Subdermal needles
Explanation - These electrodes maintain good contact over extended periods without being invasive.
Correct answer is: Skin‑contact electrodes with adhesives
Q.79 What does 'power supply rejection ratio' (PSRR) indicate in an amplifier?
Its ability to reject variations in the power supply
Its bandwidth
Its input impedance
Its noise figure
Explanation - PSRR measures how well an amplifier maintains output when supply voltage changes.
Correct answer is: Its ability to reject variations in the power supply
Q.80 Which of the following is a typical sampling frequency for an EMG sensor?
500 Hz
1 kHz
10 kHz
20 kHz
Explanation - EMG signals contain frequencies up to ~10 kHz, requiring a high sampling rate.
Correct answer is: 10 kHz
Q.81 A biomedical instrument that records electrical activity from the heart is known as:
ECG
EEG
EMG
EOG
Explanation - ECG (electrocardiogram) captures the heart's electrical signals.
Correct answer is: ECG
Q.82 Which of the following is a common method to reduce electrical noise in a biomedical instrument?
Using a high‑impedance input
Using a low‑impedance input
Increasing the amplifier gain
Decreasing the sampling rate
Explanation - A low‑impedance input reduces the effect of noise sources.
Correct answer is: Using a low‑impedance input
Q.83 Which component provides a reference voltage in many biomedical circuits?
Voltage divider
Voltage reference IC
Zener diode
Capacitor bank
Explanation - Voltage reference ICs supply a stable reference voltage for precision measurement.
Correct answer is: Voltage reference IC
Q.84 A 'photoplethysmogram' (PPG) waveform primarily shows:
Blood volume changes in the microvascular bed
Brain electrical activity
Muscle contraction force
Respiratory cycle
Explanation - PPG reflects changes in blood volume during each heartbeat.
Correct answer is: Blood volume changes in the microvascular bed
Q.85 Which type of biomedical instrument uses a capacitor to measure changes in blood volume?
Photoplethysmograph
Ultrasound Doppler
Capacitance blood volume sensor
Thermal sensor
Explanation - Capacitance sensors detect changes in capacitance caused by blood volume variations.
Correct answer is: Capacitance blood volume sensor
Q.86 In an ECG lead I, what is the polarity of the R‑wave relative to the left arm?
Positive
Negative
Zero
Variable
Explanation - Lead I records the difference between the left arm and right arm, showing a positive R‑wave.
Correct answer is: Positive
Q.87 What is the purpose of a 'blanking circuit' in a biomedical instrument?
To prevent the amplifier from reacting to large transients
To amplify low‑frequency signals
To filter out high‑frequency noise
To power the device
Explanation - Blanking circuits protect the input during large voltage spikes.
Correct answer is: To prevent the amplifier from reacting to large transients
Q.88 Which of the following best describes an 'integrated wearable ECG monitor'?
A patch that records ECG and streams data wirelessly
A chest strap that only records ECG offline
An implantable ECG sensor that requires surgery
A handheld ECG recorder with cables
Explanation - Wearable ECG patches typically capture data and transmit it to a phone or cloud.
Correct answer is: A patch that records ECG and streams data wirelessly
Q.89 The main advantage of a digital signal processor (DSP) in biomedical instrumentation is:
Real‑time data processing
Reduced power consumption
Smaller size
Lower cost
Explanation - DSPs enable rapid, on‑device computation of complex algorithms.
Correct answer is: Real‑time data processing
Q.90 Which of the following is an example of a 'soft‑tissue' sensor in biomedical instrumentation?
Intra‑arterial catheter
Skin‑mounted accelerometer
Intracranial electrode
Endoscopic camera
Explanation - Soft‑tissue sensors are attached to or placed on soft body tissues.
Correct answer is: Skin‑mounted accelerometer
Q.91 What is the typical output of a capacitive pressure sensor in a biomedical cuff?
Voltage
Current
Frequency
Temperature
Explanation - Capacitive sensors output a voltage proportional to the pressure applied.
Correct answer is: Voltage
Q.92 Which of the following best describes the role of a 'microcontroller' in a biomedical device?
To amplify the signal
To sample the signal
To process data and control peripherals
To provide power
Explanation - Microcontrollers manage data processing, user interface, and device control.
Correct answer is: To process data and control peripherals
Q.93 Which of these is NOT a typical safety feature in a wearable medical device?
Automatic shut‑off on over‑current
Temperature monitoring
High‑gain amplifiers
Data encryption
Explanation - High‑gain amplifiers are not directly related to safety but to performance.
Correct answer is: High‑gain amplifiers
Q.94 In an ECG system, the 'T' wave represents:
Ventricular depolarization
Ventricular repolarization
Atrial depolarization
Atrial repolarization
Explanation - The T wave corresponds to the recovery phase of ventricular muscle cells.
Correct answer is: Ventricular repolarization
Q.95 Which type of filter would you use to eliminate 60‑Hz power‑line interference from an ECG signal?
Notch filter
Band‑pass filter
High‑pass filter
Low‑pass filter
Explanation - A notch filter removes a narrow frequency band, such as 60 Hz.
Correct answer is: Notch filter
Q.96 What is the purpose of a 'zero‑balance' circuit in an instrumentation amplifier?
To cancel DC offset
To increase gain
To provide a reference voltage
To reduce noise
Explanation - Zero‑balance removes any DC offset that would otherwise affect the AC signal.
Correct answer is: To cancel DC offset
Q.97 Which of the following is a typical frequency range for a photoplethysmographic sensor?
0.1–2 Hz
2–5 Hz
5–20 Hz
20–100 Hz
Explanation - PPG signals are dominated by the heart rate (~1–2 Hz).
Correct answer is: 0.1–2 Hz
Q.98 In a biomedical instrument, which parameter is most important for determining the dynamic range of an ADC?
Resolution
Sampling rate
Noise figure
Power supply voltage
Explanation - Resolution (bits) sets the smallest detectable change and influences dynamic range.
Correct answer is: Resolution
Q.99 Which of the following best describes the function of a 'rectifier' in a biomedical circuit?
To convert AC to DC
To filter high‑frequency signals
To amplify low‑frequency signals
To generate random noise
Explanation - A rectifier converts alternating current to a unidirectional current.
Correct answer is: To convert AC to DC
Q.100 What is the main function of an 'integrated circuit' (IC) used as a reference voltage in biomedical instrumentation?
Provide a stable voltage source
Amplify the signal
Digitize analog signals
Control the power supply
Explanation - Reference ICs generate precise, stable voltages required for accurate measurement.
Correct answer is: Provide a stable voltage source
Q.101 Which of the following is a typical method to secure electrodes on a patient’s skin during a long ECG recording?
Use of adhesive strips
Soldering electrodes directly to the skin
Intracutaneous needles
Leaving them unattached
Explanation - Adhesive electrodes maintain consistent contact over extended periods.
Correct answer is: Use of adhesive strips
Q.102 Which biomedical device uses a 'piezoelectric' sensor to detect heartbeats?
Digital blood pressure cuff
Electrocardiograph
Pulse oximeter
Temperature sensor
Explanation - Piezoelectric transducers can convert mechanical heart vibrations into electrical signals.
Correct answer is: Electrocardiograph
Q.103 In a biomedical instrument, the 'gain' of an amplifier is defined as:
Output voltage divided by input voltage
Input voltage divided by output voltage
Output current divided by input current
Input current divided by output current
Explanation - Gain = Vout/Vin, indicating how much the input is amplified.
Correct answer is: Output voltage divided by input voltage
Q.104 Which of the following is a common source of electromagnetic interference (EMI) in a hospital setting?
MRI machine
Computer monitors
MRI scanner
All of the above
Explanation - All listed equipment can produce EMI that affects sensitive biomedical devices.
Correct answer is: All of the above
Q.105 In a biomedical device, a 'feedback resistor' is used to:
Set the amplifier gain
Set the input impedance
Generate a reference voltage
Provide power to the device
Explanation - In an op‑amp, a feedback resistor determines the closed‑loop gain.
Correct answer is: Set the amplifier gain
Q.106 Which of the following is an example of a 'non‑invasive' monitoring device?
Arterial line
Pulse oximeter
Central venous catheter
Intravascular ultrasound
Explanation - Pulse oximetry measures oxygen saturation through the skin without penetration.
Correct answer is: Pulse oximeter
Q.107 What does 'SNR' stand for in the context of biomedical signals?
Signal‑to‑Noise Ratio
Sampling Rate Noise
Signal Normalization Ratio
Standard Noise Reduction
Explanation - SNR quantifies how strong the desired signal is relative to background noise.
Correct answer is: Signal‑to‑Noise Ratio
Q.108 Which of the following is typically the highest impedance electrode used in EEG?
Ag/AgCl electrode
Gold electrode
Silver electrode
Copper electrode
Explanation - Ag/AgCl electrodes are chosen for their low and stable impedance.
Correct answer is: Ag/AgCl electrode
Q.109 Which of the following components is required to convert a 0–3.3 V analog signal into a 0–5 V digital signal for a microcontroller?
Voltage divider
Level shifter
Amplifier
Oscillator
Explanation - A level shifter adjusts the voltage range to match the microcontroller’s input limits.
Correct answer is: Level shifter
Q.110 Which of the following is a typical bandwidth requirement for an EEG amplifier?
0.1–50 Hz
1–100 kHz
5–500 Hz
10–10,000 Hz
Explanation - EEG signals are within 0.1–50 Hz, so the amplifier bandwidth is set accordingly.
Correct answer is: 0.1–50 Hz
Q.111 What does 'DAC' stand for?
Digital‑to‑Analog Converter
Direct‑Analog Circuit
Data Acquisition Controller
Differential Amplifier Circuit
Explanation - A DAC converts digital values into corresponding analog voltages or currents.
Correct answer is: Digital‑to‑Analog Converter
Q.112 Which of the following best describes an 'optical sensor' in biomedical instrumentation?
It uses light to detect physiological parameters
It measures electrical conductivity
It uses mechanical pressure
It measures temperature
Explanation - Optical sensors detect changes in light transmission or reflection to infer biological information.
Correct answer is: It uses light to detect physiological parameters
Q.113 Which of the following is NOT a standard lead in an ECG?
Lead I
Lead II
Lead III
Lead V1
Explanation - Lead V1 is a precordial (chest) lead; the standard limb leads are I, II, and III.
Correct answer is: Lead V1
Q.114 In a typical biomedical instrument, what is the purpose of a 'low‑pass filter' with a cutoff at 150 Hz?
To remove baseline wander
To remove high‑frequency noise
To extract the QRS complex
To increase the signal amplitude
Explanation - A low‑pass filter at 150 Hz lets the ECG content pass while suppressing higher‑frequency noise.
Correct answer is: To remove high‑frequency noise
Q.115 Which of the following best describes the function of an 'anti‑aliasing filter'?
To prevent high‑frequency components from being mis‑represented during digitization
To filter out low‑frequency signals
To convert analog signals to digital
To increase sampling frequency
Explanation - It limits the bandwidth so that aliasing does not occur when sampling.
Correct answer is: To prevent high‑frequency components from being mis‑represented during digitization
Q.116 Which of the following sensors is used to monitor oxygen levels in a finger?
Photodiode
Accelerometer
Thermistor
Capacitive sensor
Explanation - The photodiode detects light transmitted through the finger for SpO2 measurement.
Correct answer is: Photodiode
Q.117 In biomedical instrumentation, 'noise figure' is a measure of:
How much noise is added by the amplifier
The bandwidth of the circuit
The input impedance
The output voltage swing
Explanation - Noise figure quantifies the amplifier's contribution to the overall system noise.
Correct answer is: How much noise is added by the amplifier
Q.118 Which component is commonly used to generate a clock signal for a microcontroller in a biomedical device?
Crystal oscillator
Voltage regulator
Capacitor bank
Transistor
Explanation - Crystal oscillators provide a stable frequency reference for digital timing.
Correct answer is: Crystal oscillator
Q.119 Which of the following is a typical measurement unit for blood pressure?
mmHg
Pa
N/m²
V
Explanation - Blood pressure is commonly expressed in millimeters of mercury (mmHg).
Correct answer is: mmHg
Q.120 Which of the following describes an 'electrochemical biosensor'?
A sensor that converts chemical reactions into electrical signals
A sensor that uses light to measure physiological parameters
A sensor that measures mechanical pressure
A sensor that detects magnetic fields
Explanation - Electrochemical biosensors detect analytes through chemical reactions that produce a measurable current or voltage.
Correct answer is: A sensor that converts chemical reactions into electrical signals
Q.121 In an ECG recording, the 'PR interval' represents:
Time from atrial depolarization to ventricular depolarization
Time from ventricular depolarization to ventricular repolarization
Duration of the QRS complex
Time from P wave to T wave
Explanation - The PR interval is the period from the onset of the P wave to the start of the QRS complex.
Correct answer is: Time from atrial depolarization to ventricular depolarization
Q.122 What is the function of a 'voltage reference' in a biomedical instrument?
Provide a stable reference voltage for accurate measurements
Amplify the input signal
Convert analog to digital
Control the power supply
Explanation - A voltage reference sets a known voltage against which other signals are compared.
Correct answer is: Provide a stable reference voltage for accurate measurements
Q.123 Which type of biomedical sensor is most suitable for measuring blood glucose levels in a fingerstick test?
Glucose oxidase sensor
Photodiode
Accelerometer
Thermistor
Explanation - Glucose oxidase reacts with glucose to produce an electrical signal proportional to glucose concentration.
Correct answer is: Glucose oxidase sensor
Q.124 In biomedical instrumentation, a 'differential measurement' is performed to:
Reduce common‑mode noise
Increase signal amplitude
Change the signal frequency
Control the power supply
Explanation - Differential measurement subtracts two inputs, canceling signals common to both.
Correct answer is: Reduce common‑mode noise
Q.125 Which component in a pulse oximeter helps to filter out ambient light interference?
Band‑pass filter
Low‑pass filter
High‑pass filter
Notch filter
Explanation - A band‑pass filter allows only the desired frequency range while rejecting other light frequencies.
Correct answer is: Band‑pass filter
Q.126 Which of the following is a common safety standard for medical electrical equipment?
IEC 60601-1
ISO 9001
ISO 14001
ISO 21001
Explanation - IEC 60601-1 specifies safety and performance requirements for medical electrical equipment.
Correct answer is: IEC 60601-1
Q.127 What is the typical range of the 'R' wave amplitude in a standard ECG?
0.1–0.5 mV
1–2 mV
10–20 mV
100–200 mV
Explanation - The R wave amplitude is usually 1–2 mV in a standard ECG.
Correct answer is: 1–2 mV
Q.128 Which of the following is a typical input impedance of an instrumentation amplifier in a biomedical circuit?
10 kΩ
100 kΩ
1 MΩ
10 MΩ
Explanation - Instrumentation amplifiers often have very high input impedance to minimize loading.
Correct answer is: 10 MΩ
Q.129 Which of the following components is used to provide power to a wearable biomedical sensor?
Rechargeable battery
Capacitor bank
Voltage regulator
All of the above
Explanation - Wearable devices rely on rechargeable batteries as their primary power source.
Correct answer is: Rechargeable battery
Q.130 Which of these sensors is typically used in a heart rate monitor?
Photoplethysmograph
Accelerometer
Thermistor
Capacitive sensor
Explanation - A photoplethysmograph detects blood volume changes to calculate heart rate.
Correct answer is: Photoplethysmograph
Q.131 Which of the following is a typical method to reduce motion artifact in an ECG?
High‑gain amplification
Proper electrode placement and secure attachment
Increasing the sampling frequency
Using a low‑pass filter only
Explanation - Secure electrodes minimize motion artifact by maintaining consistent contact.
Correct answer is: Proper electrode placement and secure attachment
Q.132 In biomedical instrumentation, which type of sensor is used to measure the electrical activity of muscles?
EMG sensor
ECG sensor
EEG sensor
PPG sensor
Explanation - EMG sensors record electrical signals generated during muscle contraction.
Correct answer is: EMG sensor
Q.133 What does the 'T' wave in an ECG represent?
Atrial repolarization
Ventricular repolarization
Atrial depolarization
Ventricular depolarization
Explanation - The T wave indicates the recovery phase of the ventricles.
Correct answer is: Ventricular repolarization
Q.134 Which of the following is a typical use of a 'low‑noise pre‑amplifier' in EEG systems?
Reduce signal amplitude
Increase signal amplitude without adding noise
Convert analog to digital
Provide power supply
Explanation - It amplifies the weak EEG signal while maintaining a high SNR.
Correct answer is: Increase signal amplitude without adding noise
Q.135 Which of the following best describes the function of a 'microcontroller' in a biomedical device?
Amplify signals
Process data and control peripherals
Generate light
Provide power
Explanation - The microcontroller handles digital signal processing and device control tasks.
Correct answer is: Process data and control peripherals
Q.136 Which component is most commonly used to supply a stable voltage reference in an ECG front‑end?
Zener diode
Voltage reference IC
Capacitor bank
Resistor ladder
Explanation - A dedicated voltage reference IC provides a precise, stable reference voltage.
Correct answer is: Voltage reference IC
Q.137 In a biomedical instrument, which type of filter would be used to remove 50 Hz mains interference?
Notch filter at 50 Hz
Band‑pass filter at 50 Hz
Low‑pass filter at 50 Hz
High‑pass filter at 50 Hz
Explanation - A notch filter precisely removes a narrow frequency band (50 Hz).
Correct answer is: Notch filter at 50 Hz