Electrical Measurements and Instrumentation MCQs (Part-15)
What is used to measure the torque applied to a rotating object?
A Force gauge
B Torque sensor
C Strain gauge
D Tachometer
A torque sensor measures the rotational force or torque applied to a rotating object. It works by detecting the twisting or deformation in the object and converting that into an electrical signal. It is commonly used in motors and machines for precise torque measurement.
How does an eddy current torque sensor work?
A By measuring resistance changes
B By detecting magnetic fields
C By measuring vibrations
D By detecting speed
Eddy current torque sensors detect the change in magnetic fields induced by a rotating shaft. As the shaft twists, the eddy currents change, and this is used to calculate the torque applied. This method is non-contact and widely used in industrial applications.
What type of sensor is typically used to measure mechanical torque?
A Piezoelectric sensor
B Strain gauge
C Optical sensor
D Capacitive sensor
Strain gauges are commonly used in torque sensors to measure the deformation or strain produced by torque. The strain gauge detects changes in resistance when the material deforms due to applied torque, providing precise torque measurements.
Which of the following reduces electrical noise in a measurement system?
A High-frequency filters
B Low-pass filters
C Shielding
D Amplifiers
Shielding is the most common method used to reduce electrical noise in a measurement system. It involves surrounding sensitive components with a conductive material to block electromagnetic interference (EMI) and prevent noise from affecting the accuracy of measurements.
What is the primary purpose of using a low-pass filter in a measurement system?
A Increase signal strength
B Eliminate high-frequency noise
C Improve signal speed
D Measure resistance
A low-pass filter is used to eliminate high-frequency noise from signals while allowing low-frequency signals to pass through. This is particularly important in measurements where noise can distort accurate readings, ensuring cleaner and more reliable data.
Which method is commonly used to reduce interference in electrical systems?
A Signal amplification
B Shielding and grounding
C Increasing signal voltage
D Increasing sampling rate
Shielding and grounding are the most effective methods for reducing electromagnetic interference (EMI) in electrical systems. Shielding prevents external noise from entering the system, while grounding helps dissipate unwanted electrical currents safely to the ground.
What is electrical noise in a measurement system?
A A constant signal
B A fluctuating signal
C Unwanted electrical signals
D A type of power loss
Electrical noise refers to any unwanted electrical signals or interference that can distort or mask the desired measurement signals. Noise can come from various sources, including electromagnetic interference (EMI), and can affect the accuracy of measurements.
What is the effect of electrical noise on measurements?
A Increases precision
B Reduces signal quality
C Increases power consumption
D Improves response time
Electrical noise reduces the quality of measurements by distorting or masking the desired signal. This can lead to inaccurate readings and misinterpretations, especially in sensitive measurement systems where precision is critical.
What is used to measure torque in high-speed rotating systems?
A Tachometer
B Rotary encoder
C Optical sensor
D Strain gauge
Optical sensors are often used to measure torque in high-speed rotating systems due to their non-contact nature and ability to provide high precision. They work by detecting changes in light patterns caused by torque-induced deformation in the rotating shaft.
What type of noise reduction technique is most effective in reducing power-line interference?
A High-pass filters
B Low-pass filters
C Grounding
D Shielding
Grounding is effective in reducing power-line interference by providing a safe path for unwanted electrical currents. It helps in dissipating noise or unwanted signals generated by power lines, which can affect sensitive equipment and measurements.
What does a torque sensor measure?
A Linear displacement
B Rotational force
C Fluid pressure
D Temperature
A torque sensor measures the rotational force applied to an object, such as a shaft or axle. It converts the twisting force into an electrical signal that can be processed and analyzed to determine the amount of torque being applied.
Which type of flow meter is used for high-precision flow measurements?
A Magnetic flow meter
B Coriolis flow meter
C Ultrasonic flow meter
D Rotameter
A Coriolis flow meter is highly accurate and widely used for precise flow measurement. It works by detecting the change in vibration caused by the flow of fluid through the meter, providing accurate mass flow measurement even for high-viscosity fluids.
What type of sensor is commonly used for torque measurement in automotive applications?
A Strain gauge sensor
B Piezoelectric sensor
C Capacitive sensor
D Optical sensor
Strain gauge sensors are widely used in automotive applications to measure torque. They detect the deformation of materials caused by applied torque and convert this into a measurable electrical signal, providing accurate torque data for engine performance and testing.
What is the role of a low-pass filter in electrical measurement systems?
A Allow all frequencies
B Remove high-frequency components
C Increase signal strength
D Prevent signal degradation
A low-pass filter allows low-frequency signals to pass through while removing high-frequency noise. This is particularly useful in electrical measurement systems to reduce unwanted high-frequency interference and ensure the accuracy of the desired signal.
Which of these is a method of improving the accuracy of torque measurement?
A Using a high-speed sensor
B Increasing the signal frequency
C Using a calibration standard
D Using a low-pass filter
Using a calibration standard ensures that the torque measurement system is providing accurate results. Calibration compares the sensor readings with known reference values, adjusting the system to correct any deviations, thus improving measurement accuracy.