Electrical Measurements and Instrumentation MCQs (Part-7)
What is the main purpose of signal conditioning in measurement systems?
A Convert signals
B Amplify signals
C Filter noise
D Improve signal quality
Signal conditioning modifies raw sensor signals into a form suitable for measurement and processing. It involves filtering noise, amplifying weak signals, or converting analog signals to digital, ensuring accurate data acquisition and reliable measurement.
Which device is used to convert mechanical displacement into an electrical signal?
A Temperature sensor
B Displacement sensor
C Flow meter
D Strain gauge
A displacement sensor converts the mechanical movement or position of an object into an electrical signal. It is commonly used in applications like robotics, machinery monitoring, and structural testing to measure linear or angular displacement.
What does a data acquisition system primarily do?
A Collect and process data
B Control electrical flow
C Display power readings
D Measure current
A data acquisition system (DAQ) collects, measures, and processes electrical signals from sensors or instruments. It converts analog signals to digital form and provides accurate data for analysis, often used in research, industrial applications, and testing.
What type of measurement is a thermocouple used for?
A Displacement
B Pressure
C Temperature
D Strain
A thermocouple measures temperature by generating a voltage that is proportional to the temperature difference between two junctions. It is widely used due to its simplicity, fast response, and ability to measure a wide temperature range.
Which instrument is used to measure fluid flow in pipes?
A Strain gauge
B Pressure sensor
C Thermocouple
D Flow meter
A flow meter measures the rate of flow of liquids or gases through pipes or ducts. It helps in various industries to ensure proper flow rates in systems such as water treatment plants, oil refineries, and HVAC systems.
What does a piezoelectric sensor measure?
A Vibration
B Strain
C Pressure
D Temperature
A piezoelectric sensor measures vibration, pressure, or acceleration by converting mechanical stress into an electrical charge. It is commonly used in applications like machinery condition monitoring, earthquake detection, and structural health monitoring.
What is the function of a sensor in a measurement system?
A Amplify signals
B Convert energy
C Measure physical quantity
D Convert analog to digital
A sensor is designed to detect and measure a physical quantity (such as temperature, pressure, or displacement) and convert it into an electrical signal. This signal is then used for further processing or data analysis in measurement systems.
What is the primary function of a current transformer (CT)?
A Measure power
B Step down current
C Step down voltage
D Measure resistance
A current transformer (CT) is used to step down high currents to safer, measurable levels for instruments. It provides electrical isolation and ensures the safety of measuring devices while accurately monitoring current flow in power systems.
Which of the following is used to measure very small currents?
A Voltmeter
B Ammeter
C Wattmeter
D Galvanometer
A galvanometer is used to measure small electrical currents with high sensitivity. It operates based on the deflection of a needle due to the magnetic field created by current flowing through a coil, commonly used in precision measurements.
What does an oscillograph display?
A Waveforms
B Frequency
C Power
D Voltage
An oscillograph, or oscilloscope, displays the waveform of an electrical signal. It shows how a signal’s voltage changes over time, allowing engineers and technicians to analyze and troubleshoot electrical signals in circuits.
What does a strain gauge measure?
A Voltage
B Strain
C Temperature
D Pressure
A strain gauge measures the deformation (strain) in a material when subjected to a force. As the material deforms, the resistance of the strain gauge changes, and this change is used to calculate the strain.
Which device is used to measure the flow of electrical current in a circuit?
A Ohmmeter
B Wattmeter
C Voltmeter
D Ammeter
An ammeter is used to measure the electric current flowing through a circuit. It is connected in series with the circuit and is designed to measure both direct and alternating currents with high accuracy.
What is the purpose of a pressure sensor?
A Measure power
B Measure temperature
C Measure pressure
D Measure voltage
A pressure sensor measures the force exerted by a fluid (liquid or gas) on a surface. It is commonly used in industrial applications such as monitoring air pressure in tanks, systems, and hydraulic machinery for safe operation.
What does a potentiometer measure?
A Voltage
B Resistance
C Current
D Power
A potentiometer is used to measure unknown voltages by balancing them against a known reference. It is a precise tool often used in laboratory settings and for calibration purposes to ensure accurate voltage measurements.
Which device is commonly used for measuring very high voltages?
A High voltage probe
B Multimeter
C Frequency meter
D Galvanometer
A high voltage probe is designed to safely measure voltages in high voltage systems. It provides a scaled down measurement to prevent damage to measuring instruments and ensures accurate readings in environments with electrical stress.