Sensors and Transducers: A Comprehensive Guide for Medical Physics and Biomedical Engineering Students

Question 1

Which of the following is not considered a type of sensor?

Accepted Answer

Actuator

Answer

Transducer

Answer

Optical

Answer

Chemical

Question 2

What is the main function of a transducer?

Accepted Answer

To convert a physical quantity into an electrical signal

Answer

To amplify electrical signals

Answer

To process data

Answer

To display data

Question 3

What is the underlying principle behind optical sensors?

Accepted Answer

Absorption and reflection of light

Answer

Electrical resistance

Answer

Magnetic field detection

Answer

Capacitance

Question 4

Which of the following is a common type of chemical sensor?

Accepted Answer

pH electrode

Answer

Strain gauge

Answer

Accelerometer

Answer

Microphone

Question 5

What is the primary purpose of a piezoelectric sensor?

Accepted Answer

To convert mechanical stress into an electrical signal

Answer

To convert light into an electrical signal

Answer

To convert chemical reactions into an electrical signal

Answer

To convert heat into an electrical signal

Question 6

In medical devices, what is the primary distinction between a sensor and a transducer?

Accepted Answer

Sensors detect physical quantities (e.g., temperature), while transducers convert these measurements into electrical signals.

Answer

Sensors provide more precise measurements than transducers.

Answer

Sensors do not require an external power source, unlike transducers.

Answer

Sensors are exclusively used for medical imaging, whereas transducers have broader applications.

Question 7

Which characteristic is undesirable in an ideal sensor?

Accepted Answer

Non-linear response

Answer

Low noise

Answer

Fast response time

Answer

High sensitivity

Question 8

A transducer that converts electrical signals to mechanical motion is called a:

Accepted Answer

Electromagnetic actuator

Answer

Thermocouple

Answer

Piezoelectric sensor

Answer

Phototransistor

Question 9

Which sensor is commonly used to measure temperature in medical applications?

Accepted Answer

Thermistor

Answer

pH electrode

Answer

Strain gauge

Answer

Accelerometer

Question 10

The output of a strain gauge is:

Accepted Answer

Proportional to the strain

Answer

Independent of the strain

Answer

Randomly distributed

Answer

Inversely proportional to the strain

Question 11

An example of a passive transducer is:

Accepted Answer

Thermocouple

Answer

Operational amplifier

Answer

Transistor

Answer

Photomultiplier

Question 12

The sensitivity of a sensor is defined as its:

Accepted Answer

Output change per unit change in input

Answer

Difference between output and input

Answer

Input change per unit change in output

Answer

Ratio of output to input

Question 13

A transducer that converts mechanical displacement into an electrical signal is known as:

Accepted Answer

Linear variable differential transformer (LVDT)

Answer

Phototransistor

Answer

Thermocouple

Answer

Piezoelectric sensor

Question 14

Which of the following is a type of resistive sensor?

Accepted Answer

Strain gauge

Answer

Capacitive sensor

Answer

Hall effect sensor

Answer

Thermocouple

Question 15

The bandwidth of a sensor represents:

Accepted Answer

The range of frequencies it can operate within

Answer

Its minimum measurable frequency

Answer

Its maximum measurable frequency

Question 16

Which characteristic is undesirable in a transducer?

Accepted Answer

High hysteresis

Answer

Low drift

Answer

Good linearity

Answer

High sensitivity

Question 17

A strain gauge is a type of sensor that converts:

Accepted Answer

Mechanical strain into an electrical signal

Answer

Magnetic field into current

Answer

Temperature into light

Answer

Chemical concentration into voltage

Question 18

The principle of operation of a thermocouple relies on which effect?

Accepted Answer

Seebeck effect

Answer

Piezoelectric effect

Answer

Hall effect

Answer

Magnetic induction

Question 19

The frequency response of a transducer is defined as:

Accepted Answer

The range of frequencies over which it operates effectively

Answer

The maximum amplitude of the output signal

Answer

The time it takes to respond to an input change

Question 20

Which factor can potentially impact the accuracy of a transducer?

Accepted Answer

Temperature

Answer

Shape

Answer

Color

Answer

Size

Question 21

The sensitivity of a transducer is expressed in terms of:

Accepted Answer

Output per unit input

Answer

Output squared per unit input

Answer

Input per unit output

Answer

Input squared per unit output

Question 22

Which type of transducer does not require direct contact with the measurand?

Accepted Answer

Optical sensor

Answer

Resistive transducer

Answer

Capacitive transducer

Answer

Strain gauge

Question 23

Hysteresis in a transducer refers to:

Accepted Answer

The difference between the output and input during a cycle

Answer

The maximum possible value of the output

Answer

The time delay between the input and output

Question 24

Which of the following is an application of sensors and transducers in medical devices?

Accepted Answer

Monitoring vital signs

Answer

Generating electricity

Answer

Operating washing machines

Answer

Controlling traffic lights

Question 25

What is the primary function of a transducer in medical devices?

Accepted Answer

Converting a physical or chemical signal into an electrical signal

Answer

Filtering electrical noise

Answer

Amplifying electrical signals

Question 26

What is the key characteristic of a thermistor that makes it suitable for temperature sensing?

Accepted Answer

Electrical resistance changes with temperature

Answer

Generates voltage when heated

Answer

Low power consumption

Question 27

Which of the following is an advantage of using fiber optic sensors in medical devices?

Accepted Answer

Immune to electromagnetic interference

Answer

Fragile nature

Answer

Limited bandwidth

Answer

High power consumption

Question 28

What is the principle of operation of a capacitive sensor?

Accepted Answer

Change in capacitance due to proximity or contact

Answer

Generation of voltage

Answer

Change in inductance

Question 29

Which of the following applications utilizes the piezoelectric effect?

Accepted Answer

Ultrasound imaging

Answer

X-ray imaging

Answer

Magnetic resonance imaging

Answer

Computed tomography

Question 30

What is the primary function of a transducer in medical instrumentation?

Accepted Answer

Converting a non-electrical physical quantity into an electrical signal

Answer

Filtering noise from signals

Answer

Amplifying electrical signals

Question 31

What is the purpose of using Hall effect sensors in medical devices?

Accepted Answer

Measuring magnetic fields

Answer

Detecting temperature

Answer

Detecting pressure

Answer

Measuring flow rate

Question 32

What is the primary purpose of signal amplification in medical instrumentation?

Accepted Answer

Increasing the magnitude of sensor signals

Answer

Filtering noise from signals

Answer

Converting analog signals to digital

Answer

Modifying signal characteristics

Question 33

What is the importance of linearization in medical sensor systems?

Accepted Answer

Improving measurement accuracy over a wide input range

Answer

Simplifying sensor calibration

Answer

Reducing sensor drift

Answer

Increasing sensor sensitivity

Question 34

Which of the following characteristics is undesirable in a good sensor?

Accepted Answer

High sensitivity to external factors unrelated to the measured variable

Answer

Fast response time

Answer

High accuracy and precision

Question 35

A transducer that specifically converts pressure into an electrical signal is called a:

Accepted Answer

Pressure transducer

Answer

Thermistor

Answer

Accelerometer

Answer

Photodiode

Question 36

What is a primary application of a temperature sensor in medical devices?

Accepted Answer

Monitoring body temperature in a patient

Answer

Detecting blood pressure

Answer

Monitoring blood flow

Answer

Measuring muscle activity

Question 37

In a blood glucose meter, which type of sensor is typically employed?

Accepted Answer

Electrochemical sensor

Answer

Optical sensor

Answer

Capacitive sensor

Answer

Piezoelectric sensor

Question 38

A strain gauge, a sensor commonly used to measure force or pressure, operates based on the principle of:

Accepted Answer

Change in electrical resistance due to deformation

Answer

Change in capacitance due to distance variation

Answer

Change in magnetic field due to motion

Answer

Change in light intensity due to absorption

Question 39

The sensitivity of a sensor is defined as its:

Accepted Answer

Output change per unit change in the measured variable

Answer

Accuracy of measurement

Answer

Ability to withstand environmental conditions

Question 40

Using a digital sensor over an analog sensor in medical devices offers the advantage of:

Accepted Answer

Improved signal-to-noise ratio and reduced susceptibility to interference

Answer

Lower cost

Answer

Higher sensitivity

Question 41

In an ECG (Electrocardiogram) machine, which type of sensor is utilized to detect electrical signals from the heart?

Accepted Answer

Electrodes

Answer

Piezoelectric crystals

Answer

Thermistors

Answer

Optical fibers

Question 42

The essential function of a transducer in a medical device is to:

Accepted Answer

Convert a physical quantity into an electrical signal for processing

Answer

Amplify the electrical signal

Answer

Filter unwanted signals

Question 43

In a biomedical imaging system, such as MRI or CT, which type of sensor is commonly used to convert light into an electrical signal?

Accepted Answer

Photodiode

Answer

Piezoelectric sensor

Answer

Strain gauge

Answer

Thermistor