Sensors and Transducers Questions and Answers for Viva

Answer-1: A sensor is a device that is used to convert physical quantities such as light, heat, temperature, pressure, motion or humidity into electrical signals that can be measured and analyzed.

Answer-2: A thermocouple is a type of temperature sensor that is used to measure temperature by measuring the voltage between two different metals that are joined at one end.

Answer-3: The function of a sensor is to gather information about the environment or a process and convert it into a form that can be interpreted and utilized by other components or systems.

Answer-4: Sensors can be classified into various types based on their working principles, including resistive, capacitive, inductive, optical, piezoelectric, and magnetic sensors, among others.

Answer-5: A resistive sensor changes its resistance in response to a physical stimulus, such as pressure or temperature, allowing the measurement of the stimulus through changes in electrical resistance.

Answer-6: A capacitive sensor measures changes in capacitance resulting from changes in the dielectric properties of the sensor's environment, such as proximity or displacement.

Answer-7: An inductive sensor generates an electromagnetic field and detects changes in inductance caused by the presence or movement of a metallic object within the field.

Answer-8: An optical sensor detects changes in light intensity, wavelength, or phase resulting from interactions between light and the sensor's environment, such as object detection, position sensing, or imaging.

Answer-9: A piezoelectric sensor generates an electrical charge in response to mechanical stress or deformation, such as pressure, acceleration, or vibration.

Answer-10: A magnetic sensor detects changes in magnetic fields and produces electrical signals proportional to the strength, direction, or proximity of the magnetic field.

Answer-11: Temperature sensors are used in various applications, including HVAC systems, industrial processes, medical devices, automotive systems, and environmental monitoring.

Answer-12: A transducer is a device that converts one form of energy into another. It typically converts a physical quantity, such as pressure, temperature, or displacement, into an electrical signal or vice versa.

Answer-13: The two main categories of transducers are input transducers, which convert physical quantities into electrical signals, and output transducers, which convert electrical signals into physical quantities.

Answer-14: Active transducers require an external power source to operate and typically provide a measurable output signal, while passive transducers do not require external power and may alter the magnitude of the input signal without adding energy to it.

Answer-15: A resistive transducer changes its electrical resistance in response to the physical quantity being measured, such as pressure, temperature, or strain.

Answer-16: A capacitive transducer changes its capacitance in response to changes in the physical quantity being measured, such as displacement, pressure, or humidity.

Answer-17: An LVDT transducer measures linear displacement by detecting changes in the electromagnetic coupling between a movable core and two secondary windings wound on a cylindrical form.

Answer-18: A Hall effect transducer measures magnetic fields by detecting the voltage generated perpendicular to the current flow in a conductor when it is subjected to a magnetic field.

Answer-19: Pressure transducers are used in applications such as industrial process control, automotive systems, aerospace, HVAC, medical devices, and environmental monitoring.

Answer-20: Factors to consider when selecting a transducer include the type and range of the physical quantity being measured, accuracy, sensitivity, response time, environmental conditions, size, cost, and compatibility with the measurement system.