What is the unit of frequency in a frequency meter?
A Amperes
B Volts
C Hertz (Hz)
D Ohms
Frequency is measured in Hertz (Hz), which represents the number of cycles per second in an alternating current (AC) signal.
What is the main function of a Kelvin bridge?
A Measure low resistance accurately
B Measure inductance
C Measure capacitance
D Measure power
Kelvin bridges are designed to measure low resistances with high accuracy by eliminating errors from lead and contact resistance.
What is the main principle used by a Hall effect sensor?
A Voltage induced by a magnetic field
B Current induced by voltage
C Resistance change with strain
D Capacitance change with temperature
Hall effect sensors detect current by measuring the voltage induced by a magnetic field perpendicular to the current flow.
What is the purpose of using a Venturi meter?
A Measure fluid flow rate
B Measure pressure
C Measure temperature
D Measure voltage
Venturi meters measure the flow rate of fluids by detecting pressure differences across a narrowing section of a pipe.
What type of instrument is used to measure small displacements?
A Thermocouple
B LVDT (Linear Variable Differential Transformer)
C Pressure sensor
D Galvanometer
LVDTs are used for precise displacement measurement by converting mechanical movement into an electrical signal using inductance.
What is the primary function of a piezoelectric sensor?
A Measure temperature changes
B Convert mechanical stress into electrical energy
C Measure voltage changes
D Measure electric current
Piezoelectric sensors generate an electrical signal when subjected to mechanical stress due to the piezoelectric effect.
What does a calibration process ensure in a measuring instrument?
A Increase the accuracy of the instrument
B Ensure that the instrument provides accurate and reliable measurements
C Reduce the size of the instrument
D Improve the signal processing speed
Calibration compares a measuring instrument with a known standard to ensure it provides accurate and reliable results.
What does an oscilloscope primarily measure?
A Voltage waveforms over time
B Current fluctuations
C Frequency response
D Electrical power consumption
An oscilloscope measures voltage signals over time, allowing users to visualize waveforms and analyze signal behaviors.
Which of the following instruments is used to measure very high resistance?
A Ammeter
B Megger
C Voltmeter
D Multimeter
A megger is used for measuring high resistance, especially insulation resistance in electrical systems.
What is the purpose of shielding in electrical measurement systems?
A Reduce electromagnetic interference (EMI)
B Increase signal strength
C Improve accuracy of instruments
D Convert AC to DC
Shielding in electrical systems helps prevent electromagnetic interference (EMI), ensuring more accurate measurements.
Which instrument measures electrical current directly?
A Voltmeter
B Ammeter
C Wattmeter
D Galvanometer
An ammeter is used to measure the electric current flowing in a circuit by being connected in series.
What type of transformer is used to measure high currents in power systems?
A Auto transformer
B Current transformer
C Distribution transformer
D Potential transformer
Current transformers are used to step down high currents for safe measurement and protection in power systems.
Which device is used to measure phase difference between two AC signals?
A Wattmeter
B Phase meter
C Frequency meter
D Oscilloscope
Phase meters measure the angular difference in phase between two alternating current signals.
What is the function of a strain gauge?
A Measure resistance
B Measure strain in materials
C Measure voltage
D Measure current
Strain gauges detect deformation by measuring changes in resistance caused by strain in the material.
What does a frequency meter measure?
A Current flow
B Frequency of AC signals
C Energy consumption
D Voltage levels
Frequency meters measure the number of cycles per second (Hertz) of an alternating current signal.
What is the primary purpose of a wattmeter?
A Measure power
B Measure current
C Measure voltage
D Measure resistance
A wattmeter is used to measure the power consumed in an electrical circuit, considering the voltage, current, and power factor.
What is the purpose of a thermocouple?
A Measure temperature
B Measure displacement
C Measure pressure
D Measure current
Thermocouples measure temperature by generating a voltage proportional to the temperature difference between two metal junctions.
Which type of instrument is used for measuring low resistances?
A Kelvin bridge
B Maxwell bridge
C Schering bridge
D Wheatstone bridge
The Kelvin bridge is specifically designed to measure low resistances by compensating for the effects of lead and contact resistances.
Which of the following is a dynamic characteristic of an instrument?
A Accuracy
B Time constant
C Sensitivity
D Precision
The time constant of an instrument indicates how quickly it responds to changes in the measured quantity.
What type of error occurs due to fluctuating environmental conditions like temperature?
A Environmental error
B Random error
C Systematic error
D Gross error
Environmental errors are caused by changes in external conditions, such as temperature and humidity, affecting the instrument’s accuracy.
What is the primary function of a potentiometer in electrical measurement?
A Compare unknown voltage with a standard
B Measure current
C Measure power
D Measure resistance
A potentiometer is used to compare an unknown voltage with a known reference voltage for high-precision voltage measurements.
Which of the following is used to measure the displacement of an object?
A LVDT
B Thermocouple
C Strain gauge
D Pressure sensor
LVDTs (Linear Variable Differential Transformers) are used to measure linear displacement by converting mechanical movement into electrical signals.
What is the principle of operation of a Hall-effect sensor?
A Voltage induced by magnetic field
B Current induced by temperature
C Resistance changes due to strain
D Capacitance change due to force
Hall-effect sensors work by generating a voltage when a current-carrying conductor is placed in a magnetic field, which is used to measure magnetic field strength or current.
Which of the following instruments measures the energy consumption of a household?
A Energy meter
B Multimeter
C Ammeter
D Oscilloscope
Energy meters measure the total energy consumed over a period, typically in kilowatt-hours (kWh), for billing purposes.
What does a piezoelectric sensor do?
A Converts mechanical stress into electrical signal
B Measures temperature variations
C Measures flow rate
D Measures displacement
Piezoelectric sensors generate an electrical signal when mechanical stress (pressure, vibration) is applied, based on the piezoelectric effect.
What does the time constant of an instrument describe?
A The instrument’s response to time-varying inputs
B The range of measurements it can make
C The accuracy of the instrument
D The sensitivity of the instrument
The time constant of an instrument indicates the time it takes to respond to changes in the input signal, often affecting how quickly the instrument settles.
What is the purpose of a signal conditioner in a measurement system?
A To convert raw signals to usable formats
B To store data
C To measure voltage
D To measure temperature
Signal conditioners modify and amplify raw signals from transducers, making them suitable for further processing or digital conversion.
Which type of error occurs due to fluctuations in the measurement environment?
A Environmental error
B Random error
C Systematic error
D Gross error
Environmental errors are caused by external factors such as temperature, humidity, or electromagnetic interference affecting measurement accuracy.
What is the purpose of a Kelvin bridge?
A To measure low resistance accurately
B To measure high resistance
C To measure capacitance
D To measure inductance
The Kelvin bridge is used to measure very low resistances, compensating for lead and contact resistances.
Which instrument is used to measure voltage directly?
A Voltmeter
B Ammeter
C Wattmeter
D Multimeter
A voltmeter is specifically used to measure the voltage across two points in a circuit.
What is the primary purpose of a voltmeter?
A Measure current
B Measure resistance
C Measure voltage
D Measure power
A voltmeter is used to measure the electrical potential difference (voltage) between two points in a circuit.
How is a voltmeter connected in a circuit?
A In series
B In parallel
C In series-parallel
D Across the load
Voltmeters are connected in parallel to the component or section of the circuit where the voltage needs to be measured.
Which principle is used in moving coil instruments?
A Electromagnetic deflection
B Electrostatic attraction
C Piezoelectric effect
D Electromagnetic induction
Moving coil instruments work on the principle of electromagnetic deflection, where a coil of wire carrying current is placed in a magnetic field.
What does a multimeter measure?
A Only current
B Voltage, current, and resistance
C Power only
D Energy consumption
A multimeter is a versatile device that can measure voltage, current, and resistance, and sometimes capacitance and frequency.
What is the working principle of a current transformer (CT)?
A Step up voltage
B Electromagnetic induction to step down current
C Measure resistance directly
D Amplify signals
Current transformers step down high currents to lower, measurable levels using the principle of electromagnetic induction.
What is the primary function of a wattmeter?
A Measure power
B Measure voltage
C Measure current
D Measure resistance
A wattmeter is used to measure the power consumed by an electrical device by multiplying voltage, current, and the power factor.
What is the purpose of a strain gauge?
A Measure voltage
B Measure strain in materials
C Measure current
D Measure pressure
Strain gauges are used to measure strain by detecting changes in resistance caused by deformation in a material.
Which bridge is used to measure inductance?
A Kelvin bridge
B Maxwell bridge
C Schering bridge
D Wheatstone bridge
Maxwell bridges are used for precise measurement of inductance by balancing the bridge with known components.
What does a multimeter measure?
A Only current
B Voltage, current, and resistance
C Only power
D Only frequency
Multimeters are capable of measuring voltage, current, and resistance, and are versatile instruments used in various electrical measurements.
What type of error is caused by random variations in measurements?
A Systematic error
B Random error
C Gross error
D Environmental error
Random errors are unpredictable and occur due to uncontrollable factors such as environmental conditions and measurement inconsistencies.
What is the primary purpose of a galvanometer?
A Measure current
B Measure small currents
C Measure power
D Measure voltage
Galvanometers are sensitive instruments used to detect and measure very small currents in electrical circuits.
What does a phase meter measure?
A Voltage difference
B Phase difference between two signals
C Frequency
D Resistance
Phase meters measure the angular phase difference between two alternating signals in AC circuits.
Which of the following is used to measure displacement?
A Thermistor
B LVDT
C Piezoelectric sensor
D Strain gauge
LVDTs (Linear Variable Differential Transformers) are used to measure linear displacement by converting mechanical motion into electrical signals.
What is the main function of a piezoelectric sensor?
A Measure displacement
B Convert mechanical stress into electrical signal
C Measure temperature
D Measure power
Piezoelectric sensors generate an electrical signal when subjected to mechanical stress, utilizing the piezoelectric effect.
Which device is used to measure the frequency of an AC signal?
A Frequency meter
B Wattmeter
C
D Voltmeter
Frequency meters are used to measure the number of cycles per second (Hertz) of an alternating current signal.
What does an energy meter measure?
A Power factor
B Total energy consumption
C Voltage
D Current
Energy meters measure the total energy consumed by an electrical system, typically expressed in kilowatt-hours (kWh).
What does a galvanometer measure?
A Small currents
B Voltage
C Power
D Frequency
Galvanometers are used to measure small currents, typically in the microampere range.
Which type of transducer converts mechanical force into an electrical signal?
A Thermocouple
B Piezoelectric transducer
C LVDT
D Strain gauge
Piezoelectric transducers convert mechanical stress or force into an electrical signal using the piezoelectric effect.
What is the primary function of a current transformer?
A To step down current for safe measurement
B To step up voltage
C To measure voltage
D To measure resistance
Current transformers (CTs) reduce high current levels to safe, measurable levels for use with instruments like ammeters or protection relays.
What is the unit of measurement for frequency?
A Volts
B Amperes
C Hertz
D Watts
Frequency is measured in Hertz (Hz), which represents the number of cycles per second of a periodic signal.