Transducers part 2.pdf

1. What is the primary function of a photovoltaic cell? A. To convert chemical energy into thermal energy B. To convert thermal energy into mechanical energy C. To convert electrical energy into light D. To convert light energy into electrical energy 2. What type of device is us...

1. What is the primary function of a photovoltaic cell? A. To convert chemical energy into thermal energy B. To convert thermal energy into mechanical energy C. To convert electrical energy into light D. To convert light energy into electrical energy 2. What type of device is used to amplify the photoelectric current generated from converting light energy? A. Phototransistor B. Photodiode C. LDR D. Solar panel 3. What is the characteristic of a photodiode that enables it to produce both voltage and current? A. P-N junction B. Light-sensitive exposed junction C. Forward bias D. Reverse bias 4. What is the primary application of a Hall Effect sensor? A. Proximity switching and positioning B. Temperature measurement C. Light emission D. Motion detection 5. What is the characteristic of the light beam produced by a laser diode? A. Diffused and incoherent B. Scattered and irregular C. Amplified and divergent D. Concentrated and coherent 6. What is the primary function of a proximity sensor? A. To detect the presence of an object B. To weigh an object C. To measure the distance of an object D. To identify the material of an object 7. What determines the color of the laser light? A. Intensity of the magnetic field B. Current flowing through the diode C. Frequency of the electrical energy D. Type of semiconductor material used 8. Which type of proximity sensor is useful for detecting metallic objects? A. Inductive Proximity Sensor B. Optical Proximity Sensor C. Capacitive Proximity Sensor D. Magnetic Proximity Sensor 9. What type of radiation is used by some proximity sensors to detect objects? A. X-ray radiation B. Ultraviolet radiation (UV) C. Infrared radiation (IR) D. Gamma radiation 10. What is the function of a PIR sensor in security systems? A. To emit infrared light B. To monitor the temperature C. To measure the humidity level D. To detect motion and trigger alarms 11. What is the primary advantage of capacitive proximity sensors? A. High accuracy in detecting objects B. Ability to detect both metallic and non-metallic objects C. Ability to detect only metallic objects D. Low power consumption 12. What is the primary function of RF diodes? A. To measure the volumetric water content in the soil B. To detect the presence of gases in the atmosphere C. To transform chemical information into signals D. To efficiently control and manipulate RF signals 13. What is the main application of electromechanical gas sensors? A. To measure the air's humidity  B. To measure the volumetric water content in the soil C. To detect the presence of gases in the atmosphere D. To control and manipulate RF signals 14. What is the principle behind the Electrode type salinity sensor? A. Measuring changes in turbidity B. Measuring changes in conductivity C. Measuring changes in electrical permittivity D. Measuring changes in refractive index 15. What is the purpose of a Turbidity Sensor? A. To determine the salinity of a solution B. To measure the refractive index of a solution C. To determine the particle concentration and purity of a solution D. To measure the electrical conductivity of a solution 16. What is the function of LDRs? A. To increase the carbon footprint by harnessing fossil fuels B. To detect or sense light intensity C. To generate current only D. To power electrical equipment from solar energy 17. What is the principle behind the operation of Infrared Spectroscopy breathalyzers? A. Detecting changes in blood pressure B. Oxidation-reduction reactions C. Electrochemical reactions D. Measuring the absorption of infrared radiation by alcohol molecules 18. How does an optical Heartbeat Sensor measure heart rate? A. By detecting changes in blood volume B. By analyzing the electrical activity of the heart C. By measuring changes in blood pressure D. By monitoring the respiratory rate 19. What is the principle behind the operation of Fuel Cell Breathalyzers? A. Electrochemical reactions B. Semiconductor oxide sensors C. Infrared spectroscopy  D. Oxidation-reduction reactions 20. What is the primary method of calibration for relative magnetometers? A. By reference to their own internal constants B. By detecting changes in the visible light spectrum C. By measuring the time lapses between the sending and receiving of an ultrasonic pulse D. By reference to a known, accurately measured magnetic field 21. What is the primary function of a transducer in an ultrasonic sensor? A. To receive and send the ultrasonic sound wave B. To measure the direction, strength, or relative change of a magnetic field C. To convert light reflected from an object into electrical signals D. To detect changes in the visible light spectrum 22. What is the primary function of an E-Nose device? A. To detect the smell of complex volatiles B. To analyze the composition of blood C. To measure heart rate in real-time D. To monitor blood pressure 23. How does a color sensor determine the color of an object? A. By processing electrical signals converted from light reflected from the object B. By measuring the time lapses between the sending and receiving of an ultrasonic pulse C. By detecting changes in the magnetic field at a particular location D. By measuring the strength of the reflected sound wave 24. What is the primary function of a magnetometer? A. To convert light reflected from an object into electrical signals B. To measure the distance of a target object by emitting ultrasonic sound waves C. To selectively detect light within the visible spectrum D. To measure the direction, strength, or relative change of a magnetic field 25. How does an ultrasonic sensor determine the distance to a target? A. By measuring the strength of the reflected sound wave B. By calculating the frequency of the emitted sound wave C. By measuring the time lapses between the sending and receiving of the ultrasonic pulse D. By detecting changes in the visible light spectrum