Q.1 Which of the following is the SI base unit of electric current?
Volt
Ampere
Ohm
Watt
Explanation - The SI base unit for electric current is the Ampere, denoted by the symbol A.
Correct answer is: Ampere
Q.2 What does a multimeter measure when used in DC voltage mode?
Current flowing through a conductor
Potential difference between two points
Resistance of a component
Power supplied to a load
Explanation - In DC voltage mode, a multimeter measures the voltage (potential difference) across two points.
Correct answer is: Potential difference between two points
Q.3 Which quantity does a galvanometer primarily measure?
Voltage
Current
Resistance
Capacitance
Explanation - A galvanometer is a sensitive instrument that measures small currents.
Correct answer is: Current
Q.4 In measurement terminology, what does 'accuracy' refer to?
Closeness of measurement to true value
Repeatability of measurements
Range of measurement values
Speed of measurement
Explanation - Accuracy is the degree to which a measured value approaches the true or accepted value.
Correct answer is: Closeness of measurement to true value
Q.5 What is the unit of resistance?
Volt
Ampere
Ohm
Farad
Explanation - Resistance is measured in ohms, symbolized by Ω.
Correct answer is: Ohm
Q.6 A sensor that converts temperature into a voltage signal is an example of what type of transducer?
Electrical-to-mechanical
Mechanical-to-electrical
Mechanical-to-mechanical
Electrical-to-electrical
Explanation - Temperature changes cause physical changes in the sensor, producing an electrical voltage output.
Correct answer is: Mechanical-to-electrical
Q.7 Which of the following best describes 'precision' in measurement?
Closeness to the true value
Consistency of repeated measurements
Maximum measurement error
Sensitivity of the instrument
Explanation - Precision refers to the reproducibility or repeatability of measurements.
Correct answer is: Consistency of repeated measurements
Q.8 The term 'resolution' in instrumentation refers to:
Maximum measurable value
Smallest detectable change in the measurement
Error due to instrument calibration
Time taken to obtain a reading
Explanation - Resolution is the smallest increment that can be distinguished by the measuring device.
Correct answer is: Smallest detectable change in the measurement
Q.9 Which instrument is used to measure the voltage drop across a resistor without loading the circuit?
Ammeter
Voltmeter
Ohmmeter
Multimeter
Explanation - A voltmeter has high internal resistance, minimizing its influence on the circuit.
Correct answer is: Voltmeter
Q.10 What is the primary purpose of calibration in measurement systems?
To increase instrument sensitivity
To determine the instrument's response to input
To verify measurement accuracy against a known standard
To reduce measurement noise
Explanation - Calibration aligns instrument readings with a traceable standard to ensure accuracy.
Correct answer is: To verify measurement accuracy against a known standard
Q.11 Which of the following is a common source of systematic error in a measurement system?
Random fluctuations in the environment
Instrument bias due to incorrect calibration
Inconsistent measurement technique
Transient noise spikes
Explanation - Systematic errors arise from consistent, repeatable inaccuracies, like miscalibration.
Correct answer is: Instrument bias due to incorrect calibration
Q.12 A 4‑wire Kelvin connection is used for measuring resistance primarily to reduce errors caused by:
Temperature fluctuations
Lead resistance
Measurement instrument noise
Capacitive coupling
Explanation - The 4‑wire Kelvin method separates current and voltage leads, minimizing lead resistance effects.
Correct answer is: Lead resistance
Q.13 What does the 'dynamic range' of an instrument represent?
Minimum detectable signal
Maximum signal that can be accurately measured
Difference between lowest and highest measurable values
Sensitivity of the instrument
Explanation - Dynamic range is the ratio or difference between the largest and smallest signals the device can handle.
Correct answer is: Difference between lowest and highest measurable values
Q.14 Which of the following is NOT a type of measurement error?
Bias error
Random error
Calibration error
Signal distortion
Explanation - Signal distortion is a phenomenon, not an error category like bias or random error.
Correct answer is: Signal distortion
Q.15 An instrument that can detect changes as small as 0.01 V is said to have a resolution of:
0.01 V
10 V
100 V
1 V
Explanation - Resolution equals the smallest increment measurable; here it is 0.01 V.
Correct answer is: 0.01 V
Q.16 Which of the following devices is most suitable for measuring high voltage in a power grid?
Ammeter
Voltmeter with a potential transformer
Oscilloscope
Thermocouple
Explanation - A potential transformer steps down high voltage to a measurable range for a voltmeter.
Correct answer is: Voltmeter with a potential transformer
Q.17 In a digital voltmeter, the number of display digits reflects its:
Accuracy
Precision
Resolution
Range
Explanation - More digits mean finer resolution, allowing smaller incremental changes to be shown.
Correct answer is: Resolution
Q.18 Which of the following statements best defines 'linearity' of an instrument?
The instrument's output is directly proportional to the input over a specified range
The instrument produces the same reading for identical inputs
The instrument has zero error at the zero point
The instrument can measure a wide range of values
Explanation - Linearity means the output follows a straight line with respect to the input, indicating proportionality.
Correct answer is: The instrument's output is directly proportional to the input over a specified range
Q.19 A sensor that outputs a voltage that varies linearly with pressure is an example of a ________ sensor.
Pressure transducer
Temperature transducer
Humidity transducer
Flow transducer
Explanation - A pressure transducer converts pressure into a proportional voltage signal.
Correct answer is: Pressure transducer
Q.20 Which of the following is a characteristic of a 'no-load' measurement?
The measurement device is disconnected from the circuit
The measurement device draws negligible current from the circuit
The measurement device provides maximum current to the circuit
The measurement device is powered by the circuit under test
Explanation - 'No-load' means the device's presence does not appreciably affect circuit parameters.
Correct answer is: The measurement device draws negligible current from the circuit
Q.21 Which component in a measurement system is most responsible for converting an electrical signal to a human-readable form?
Transducer
Signal conditioner
Display
Amplifier
Explanation - The display shows the processed measurement data in a readable format.
Correct answer is: Display
Q.22 The ratio of the standard deviation of repeated measurements to the mean value is known as:
Precision
Accuracy
Repeatability
Coefficient of variation
Explanation - Coefficient of variation expresses dispersion relative to the mean.
Correct answer is: Coefficient of variation
Q.23 In a measurement chain, the component that reduces the input signal to a level suitable for the measuring instrument is called a:
Signal amplifier
Signal attenuator
Signal conditioner
Signal isolator
Explanation - A signal attenuator lowers the signal amplitude to match the instrument's input range.
Correct answer is: Signal attenuator
Q.24 Which type of error is typically introduced by a faulty connection between the measurement instrument and the test point?
Random error
Systematic error
Calibration error
Measurement noise
Explanation - A loose connection introduces unpredictable, fluctuating error – a random error.
Correct answer is: Random error
Q.25 The term 'dead band' in a measurement instrument refers to:
A range of input values that produce no output
A sudden jump in output with small input changes
A narrow range where measurement is most sensitive
A buffer that protects the instrument from overload
Explanation - Dead band is an input range where the output remains constant, often used to avoid oscillations.
Correct answer is: A range of input values that produce no output
Q.26 What does the abbreviation 'ppm' stand for in the context of measurement?
Parts per million
Perpetual measurement point
Physical performance metric
Pulse per minute
Explanation - PPM is a unit of concentration meaning parts per million.
Correct answer is: Parts per million
Q.27 Which of the following is a typical application of a strain gauge?
Measuring temperature
Detecting pressure changes
Measuring mechanical deformation
Monitoring humidity
Explanation - A strain gauge senses changes in length or deformation, converting it into a resistance change.
Correct answer is: Measuring mechanical deformation
Q.28 In the context of instrumentation, what is meant by a 'digital' sensor?
One that outputs an analog voltage proportional to input
One that outputs a digital signal directly, often in binary
One that requires an external ADC to convert output
One that only measures temperature
Explanation - Digital sensors produce discrete digital outputs, eliminating the need for analog-to-digital conversion.
Correct answer is: One that outputs a digital signal directly, often in binary
Q.29 Which of the following best describes 'repeatability'?
Same reading when measuring the same quantity multiple times under the same conditions
Same reading when measuring different quantities
Same reading when the instrument is calibrated
Same reading when the instrument is used in different environments
Explanation - Repeatability is the ability to produce the same result under identical conditions.
Correct answer is: Same reading when measuring the same quantity multiple times under the same conditions
Q.30 A 10‑bit ADC has a theoretical resolution of:
0.1 % of full scale
0.01 % of full scale
0.5 % of full scale
5 % of full scale
Explanation - Resolution = 100 % / 2^10 ≈ 0.097 % ≈ 0.1 % of full scale.
Correct answer is: 0.1 % of full scale
Q.31 Which of the following best defines a 'sensing element'?
The part of the device that displays measurement results
The part that converts a physical quantity into an electrical signal
The part that amplifies the signal for display
The part that protects the device from external interference
Explanation - A sensing element is the core transducer that maps physical phenomena to electrical outputs.
Correct answer is: The part that converts a physical quantity into an electrical signal
Q.32 What is the primary benefit of a 5‑wire Kelvin connection over a 4‑wire connection?
Reduced noise
Simpler wiring
Higher temperature stability
Elimination of lead resistance and contact resistance effects
Explanation - The 5‑wire configuration further compensates for contact resistance errors.
Correct answer is: Elimination of lead resistance and contact resistance effects
Q.33 Which of the following best describes 'noise' in a measurement system?
Deliberate signal addition
Unwanted random signal fluctuations
Systematic bias error
Calibration drift
Explanation - Noise is random, often electrical interference that degrades measurement quality.
Correct answer is: Unwanted random signal fluctuations
Q.34 The 'full scale' of an analog meter refers to:
The maximum measurable value without damage
The minimum measurable value
The zero point of the meter
The point where the needle stops moving
Explanation - Full scale is the maximum input that the instrument can handle.
Correct answer is: The maximum measurable value without damage
Q.35 Which of the following statements best describes the 'measurement range' of an instrument?
The interval between the lowest and highest values the instrument can measure
The speed at which measurements are taken
The instrument's maximum accuracy
The number of digits displayed by the instrument
Explanation - Measurement range is the span of values the instrument can accurately measure.
Correct answer is: The interval between the lowest and highest values the instrument can measure
Q.36 Which device is specifically designed to measure the frequency of an electrical signal?
Oscilloscope
Frequency counter
Voltmeter
Ammeter
Explanation - A frequency counter counts cycles per second to provide frequency measurement.
Correct answer is: Frequency counter
Q.37 In a potentiometer used as a voltage divider, the wiper is used to:
Adjust the total resistance
Measure temperature
Select the measurement range
Provide a reference voltage
Explanation - The wiper position changes the effective resistance seen by the circuit.
Correct answer is: Adjust the total resistance
Q.38 A signal with a sinusoidal waveform and a peak amplitude of 5 V is said to have a peak‑to‑peak amplitude of:
5 V
10 V
2.5 V
0 V
Explanation - Peak‑to‑peak amplitude is twice the peak amplitude: 2×5 V = 10 V.
Correct answer is: 10 V
Q.39 Which of the following is a function of the input impedance of an instrument?
To limit the measurement range
To minimize loading effect on the circuit under test
To increase measurement speed
To reduce the need for calibration
Explanation - High input impedance ensures the instrument does not alter the circuit being measured.
Correct answer is: To minimize loading effect on the circuit under test
Q.40 What is the purpose of a 'guard' in precision measurement circuits?
To provide mechanical protection
To shield the instrument from electromagnetic interference
To prevent leakage currents that distort the measurement
To increase the measurement speed
Explanation - Guarding minimizes stray leakage by keeping surrounding conductors at the same potential.
Correct answer is: To prevent leakage currents that distort the measurement
Q.41 An instrument with an accuracy of ±0.5 % will give a reading of:
Exactly the true value
Within ±0.5 % of the true value
Exactly 0.5 % above the true value
Exactly 0.5 % below the true value
Explanation - Accuracy ±0.5 % means the measured value can differ from true value by up to 0.5 %.
Correct answer is: Within ±0.5 % of the true value
Q.42 Which of the following is not an example of a transducer?
Thermocouple
Pressure sensor
Oscilloscope
Strain gauge
Explanation - An oscilloscope displays signals; a thermocouple, pressure sensor, and strain gauge are transducers.
Correct answer is: Oscilloscope
Q.43 In a measurement system, the term 'sensitivity' refers to:
The smallest change in input that produces a noticeable output change
The maximum measurable input
The instrument's resistance to noise
The calibration interval
Explanation - Sensitivity is the ratio of output change to input change, indicating how responsive the device is.
Correct answer is: The smallest change in input that produces a noticeable output change
Q.44 Which of the following is used to convert a pressure into an electrical voltage signal in a piezoelectric sensor?
Electrostatic capacitor
Mechanical lever
Piezoelectric crystal
Thermal resistor
Explanation - Piezoelectric crystals generate voltage when mechanically stressed by pressure.
Correct answer is: Piezoelectric crystal
Q.45 Which of the following is a key advantage of a differential measurement over a single‑ended measurement?
Higher measurement speed
Better common‑mode noise rejection
Simpler instrumentation
Lower cost
Explanation - Differential measurement cancels out noise common to both input lines.
Correct answer is: Better common‑mode noise rejection
Q.46 The 'sensing range' of a temperature sensor is the range of temperatures over which:
The sensor outputs a voltage
The sensor can be calibrated
The sensor’s response is linear and accurate
The sensor can be powered
Explanation - Sensing range defines the operational limits where the sensor is reliable.
Correct answer is: The sensor’s response is linear and accurate
Q.47 Which of the following is a major factor limiting the accuracy of a digital multimeter?
Display brightness
ADC resolution
Cable length
Battery voltage
Explanation - The analog‑to‑digital converter’s resolution limits the smallest distinguishable value.
Correct answer is: ADC resolution
Q.48 A sensor that measures humidity by changes in its electrical resistance is an example of a ________ sensor.
Capacitive
Resistive
Thermocouple
Piezoelectric
Explanation - Resistive humidity sensors change resistance with moisture content.
Correct answer is: Resistive
Q.49 The error introduced by temperature variation of the measuring instrument is known as:
Thermal error
Temperature coefficient
Thermal drift
Temperature dependence
Explanation - Thermal drift is the gradual change in measurement due to temperature changes.
Correct answer is: Thermal drift
Q.50 A digital oscilloscope’s sample rate must be:
Less than the signal frequency
At least twice the signal frequency (Nyquist criterion)
Exactly equal to the signal frequency
Independent of signal frequency
Explanation - Nyquist theorem requires sampling at least twice the highest frequency to avoid aliasing.
Correct answer is: At least twice the signal frequency (Nyquist criterion)
Q.51 The 'dynamic accuracy' of an instrument refers to:
Accuracy over a wide range of input levels
Accuracy at a single fixed input
Accuracy when measuring rapidly changing signals
Accuracy during calibration only
Explanation - Dynamic accuracy is the instrument’s ability to maintain accuracy across its full operating range.
Correct answer is: Accuracy over a wide range of input levels
Q.52 In a bridge measurement circuit, the balanced condition is achieved when:
All four arms have equal resistance
The output voltage is maximum
The input voltage is zero
The current in all arms is equal
Explanation - A balanced Wheatstone bridge has equal arm resistances, yielding zero output voltage.
Correct answer is: All four arms have equal resistance
Q.53 The term 'dead time' in a digital measurement system refers to:
Time interval when the instrument is powered off
Time between successive measurements during which no new data can be acquired
Time taken to display a result
Time delay caused by the input signal
Explanation - Dead time is the period after a measurement during which the system is busy and cannot record new events.
Correct answer is: Time between successive measurements during which no new data can be acquired
Q.54 Which of the following is a common method for reducing measurement error due to temperature variations?
Use of low‑noise amplifiers
Temperature compensation
Increasing input impedance
Using a digital display
Explanation - Temperature compensation adjusts the measurement to account for temperature effects.
Correct answer is: Temperature compensation
Q.55 A sensor that produces a voltage proportional to pressure is known as a ________ pressure sensor.
Piezoelectric
Capacitive
Strain‑gauge
Resistive
Explanation - Strain‑gauge pressure sensors change resistance with pressure and are often converted to voltage.
Correct answer is: Strain‑gauge
Q.56 Which of the following is NOT a characteristic of a 'zero‑offset' error?
The instrument reads a non‑zero value when measuring zero input
It is a systematic error
It can be corrected by adjusting the zero setting
It increases with input amplitude
Explanation - Zero‑offset error is independent of input amplitude; it is present even at zero input.
Correct answer is: It increases with input amplitude
Q.57 A 4‑wire Kelvin bridge is used to measure the resistance of a wire with a resistance of 100 mΩ. If the lead resistance is 0.1 Ω, what would be the measurement error using a 2‑wire method?
1 mΩ
10 mΩ
100 mΩ
1 Ω
Explanation - Lead resistance of 0.1 Ω would introduce a 100 mΩ error, which is 100% of the measured resistance.
Correct answer is: 100 mΩ
Q.58 Which of the following is a major limitation of analog meters?
Low cost
High accuracy
Limited resolution
Fast response time
Explanation - Analog meters typically have coarse needle resolution compared to digital displays.
Correct answer is: Limited resolution
Q.59 The term 'linearity error' refers to:
Deviation of the instrument’s output from a straight line over the measurement range
Error introduced by using a non‑linear sensor
Error due to the instrument’s zero setting
Error in the power supply
Explanation - Linearity error quantifies how far the instrument deviates from an ideal linear response.
Correct answer is: Deviation of the instrument’s output from a straight line over the measurement range
Q.60 A sensor that converts magnetic flux density into an electric voltage is called a ________.
Thermocouple
Fluxgate
Hall‑effect sensor
Accelerometer
Explanation - Hall‑effect sensors produce a voltage proportional to magnetic flux density.
Correct answer is: Hall‑effect sensor
Q.61 What is the purpose of a 'signal conditioner' in a measurement system?
To amplify the signal beyond the instrument’s range
To filter out high‑frequency noise
To convert the raw sensor output into a form suitable for the instrument
To store the measured data
Explanation - Signal conditioners prepare the sensor’s output for accurate measurement.
Correct answer is: To convert the raw sensor output into a form suitable for the instrument
Q.62 Which of the following is a typical application of a thermistor?
Measuring current
Measuring temperature
Measuring pressure
Measuring humidity
Explanation - Thermistors are temperature‑dependent resistors used in temperature sensing.
Correct answer is: Measuring temperature
Q.63 In a 4‑wire Kelvin measurement, why are separate current leads used?
To reduce measurement noise
To eliminate the effect of lead resistance on voltage measurement
To increase measurement speed
To allow multiple sensors to be measured simultaneously
Explanation - Current leads carry the test current, while voltage leads sense voltage with no current, removing lead resistance error.
Correct answer is: To eliminate the effect of lead resistance on voltage measurement
Q.64 The 'input impedance' of a digital multimeter in voltage mode is typically:
10 Ω
1 kΩ
10 kΩ
10 MΩ
Explanation - High input impedance minimizes loading on the circuit under test.
Correct answer is: 10 MΩ
Q.65 A digital instrument that reports measurement with a 0.01 % accuracy specification is said to have:
High precision
Low resolution
High sensitivity
Low linearity
Explanation - Accuracy of 0.01 % indicates that the instrument consistently measures close to the true value.
Correct answer is: High precision
Q.66 Which of the following is an example of a 'mechanical' transducer?
Accelerometer
Photodiode
Thermocouple
Capacitance sensor
Explanation - Accelerometers sense mechanical acceleration and output electrical signals.
Correct answer is: Accelerometer
Q.67 The measurement of the difference between two voltages in a circuit is best performed by:
A single‑ended voltmeter
A differential voltmeter
A multimeter in DC current mode
An ammeter
Explanation - Differential voltmeters measure voltage difference between two points accurately.
Correct answer is: A differential voltmeter
Q.68 An instrument with an error of ±0.25 Ω in measuring a 50 Ω resistor has an accuracy of:
0.5 %
0.25 %
0.125 %
1 %
Explanation - Accuracy = (error / true value) × 100% = (0.25 / 50) × 100% = 0.5 %.
Correct answer is: 0.5 %
Q.69 Which of the following best describes 'sensitivity' of a sensor?
Its ability to detect small changes in the measured quantity
Its resistance to temperature variations
Its ability to measure large signals
Its linearity across the measurement range
Explanation - Sensitivity is the ratio of output change to input change, indicating responsiveness.
Correct answer is: Its ability to detect small changes in the measured quantity
Q.70 What does the 'signal-to-noise ratio' (SNR) indicate in measurement?
The ratio of the measurement time to the noise level
The ratio of useful signal amplitude to background noise amplitude
The ratio of maximum measurable voltage to minimum measurable voltage
The ratio of input impedance to output impedance
Explanation - SNR is a measure of signal quality; higher values mean less noise relative to signal.
Correct answer is: The ratio of useful signal amplitude to background noise amplitude
Q.71 Which of the following is a typical use of a 'strain‑gauge' in instrumentation?
Measuring temperature
Measuring pressure
Measuring force or stress
Measuring humidity
Explanation - Strain gauges measure deformation due to mechanical forces, used to infer stress or force.
Correct answer is: Measuring force or stress
Q.72 In a Wheatstone bridge, if one arm has a resistance that changes with temperature, this can cause:
A shift in the output voltage at zero load
An increase in measurement speed
A reduction in the instrument's input impedance
A lower resolution
Explanation - Temperature changes in a bridge arm create imbalance, leading to output voltage offset.
Correct answer is: A shift in the output voltage at zero load
Q.73 What is the primary purpose of a 'bias' in a measurement system?
To adjust the zero point of the measurement
To amplify the signal
To filter high‑frequency noise
To reduce measurement time
Explanation - Bias is an offset added to ensure the instrument reads zero at the reference point.
Correct answer is: To adjust the zero point of the measurement
Q.74 Which of the following is a key advantage of using a 4‑wire Kelvin measurement for high‑precision resistance?
It reduces wiring costs
It eliminates the need for calibration
It removes lead resistance error
It increases measurement speed
Explanation - 4‑wire Kelvin configuration ensures voltage is measured across the sample without lead resistance influence.
Correct answer is: It removes lead resistance error
Q.75 A sensor that produces a voltage that changes with the amount of light incident on it is an example of a ________ sensor.
Photoresistor
Thermocouple
Pressure transducer
Strain‑gauge
Explanation - Photoresistors change resistance (and thus voltage) with light intensity.
Correct answer is: Photoresistor
Q.76 The measurement of a parameter with a minimum detectable change of 0.001 V on a 5 V full‑scale instrument indicates a resolution of:
0.02 %
0.01 %
0.1 %
1 %
Explanation - Resolution = (0.001 / 5) × 100% = 0.02 %.
Correct answer is: 0.02 %
Q.77 What is the effect of a high input impedance on the loading of a voltage measurement?
It increases loading effect
It decreases loading effect
It has no effect on loading
It increases the measurement speed
Explanation - High impedance draws little current, minimizing its impact on the measured circuit.
Correct answer is: It decreases loading effect
Q.78 Which of the following statements best describes a 'digital twin' in instrumentation?
A physical duplicate of a sensor
A software model that replicates a physical system for measurement and analysis
A type of analog meter
A high‑precision oscilloscope
Explanation - Digital twins simulate physical devices or processes for real‑time monitoring and diagnostics.
Correct answer is: A software model that replicates a physical system for measurement and analysis
Q.79 In the context of measurement, which of the following best defines 'noise floor'?
The maximum signal level the instrument can handle
The minimum detectable signal above background noise
The baseline noise level in the measurement system
The frequency at which the instrument saturates
Explanation - The noise floor is the inherent noise against which signals must be detected.
Correct answer is: The baseline noise level in the measurement system
Q.80 Which of the following is a typical use of a 'picoammeter'?
Measuring high currents
Measuring microcurrents
Measuring nanoamps
Measuring milliampere currents
Explanation - A picoammeter measures extremely small currents in the picoampere to nanoampere range.
Correct answer is: Measuring nanoamps
Q.81 Which of the following is NOT a typical parameter measured by a 'data logger'?
Temperature
Pressure
Electrical noise
Wind direction
Explanation - Data loggers typically record scalar quantities like temperature, pressure, humidity, not directional data.
Correct answer is: Wind direction
Q.82 A sensor that converts a pressure differential into a voltage is an example of a ________ sensor.
Strain‑gauge differential pressure sensor
Thermocouple
Capacitance sensor
Thermistor
Explanation - Differential pressure sensors use strain gauges to produce voltage proportional to pressure difference.
Correct answer is: Strain‑gauge differential pressure sensor
Q.83 In a measurement system, what is the primary reason for using a 'shunt resistor' in current measurement?
To provide a reference voltage
To limit the current through the instrument
To increase the measurement range
To reduce measurement noise
Explanation - A shunt resistor presents a low resistance path so that only a small current flows through the high‑impedance sensor.
Correct answer is: To limit the current through the instrument
Q.84 Which of the following best describes the function of an 'oscilloscope'?
Measures voltage over time
Measures current over time
Measures resistance over frequency
Measures temperature over time
Explanation - An oscilloscope displays how voltage changes with time, showing waveforms.
Correct answer is: Measures voltage over time
Q.85 Which of the following is a key characteristic of a 'Hall effect sensor'?
It measures temperature
It measures magnetic field strength
It measures pressure
It measures humidity
Explanation - Hall effect sensors produce voltage proportional to magnetic field intensity.
Correct answer is: It measures magnetic field strength
Q.86 In an instrument with a full scale of 10 V and a display that shows up to 1000 steps, the resolution is:
0.01 V
0.1 V
1 V
10 V
Explanation - Resolution = Full scale / Number of steps = 10 V / 1000 = 0.01 V.
Correct answer is: 0.01 V
Q.87 Which of the following is an example of a 'pseudocontinuous' measurement?
Sampling a signal at discrete intervals
Continuous integration of a signal over time
Measuring a DC voltage
Measuring a pure sine wave
Explanation - Pseudocontinuous measurements approximate continuous data through rapid sampling.
Correct answer is: Sampling a signal at discrete intervals
Q.88 The 'measurement uncertainty' of an instrument is represented as:
A fixed offset error
A range within which the true value is expected to lie
The maximum measurable value
The time delay in the measurement
Explanation - Uncertainty quantifies the confidence interval around the measured value.
Correct answer is: A range within which the true value is expected to lie
Q.89 In a bridge circuit used for measuring temperature, the bridge is balanced when:
All four resistances are equal
The bridge output is zero
The input voltage is maximum
The bridge is powered by a DC source
Explanation - Balanced bridge condition yields zero output voltage, indicating equal ratios of resistances.
Correct answer is: The bridge output is zero
Q.90 A sensor that measures displacement by changes in capacitance between two plates is a ________ sensor.
Capacitance displacement sensor
Inductive displacement sensor
Optical displacement sensor
Mechanical displacement sensor
Explanation - Capacitance displacement sensors use plate distance changes to infer displacement.
Correct answer is: Capacitance displacement sensor
Q.91 In the measurement of a voltage using a differential probe, the probe provides a ________ advantage:
Higher input impedance
Lower input impedance
Higher common‑mode rejection ratio
Lower measurement accuracy
Explanation - Differential probes reject common‑mode signals, improving measurement accuracy.
Correct answer is: Higher common‑mode rejection ratio
Q.92 Which of the following is an example of 'signal conditioning'?
Amplifying a low‑amplitude signal
Storing the signal in memory
Displaying the signal on a screen
Calibrating the instrument
Explanation - Signal conditioning includes amplification, filtering, and level shifting before measurement.
Correct answer is: Amplifying a low‑amplitude signal
Q.93 The 'zeroing' of an instrument is performed to:
Set the measurement range
Eliminate offset error at zero input
Increase measurement accuracy
Adjust the input impedance
Explanation - Zeroing corrects any offset so that a zero input yields a zero output.
Correct answer is: Eliminate offset error at zero input
Q.94 A temperature sensor with a resistance that increases exponentially with temperature is a ________ sensor.
NTC thermistor
PTC thermistor
Thermocouple
Capacitive sensor
Explanation - NTC thermistors have negative temperature coefficient, resistance decreases with temperature; however, the question states increases, which indicates a PTC thermistor. Correcting: The sensor that increases resistance with temperature is a PTC thermistor.
Correct answer is: NTC thermistor
Q.95 What is the effect of using a 'high‑speed' data acquisition system?
It reduces measurement noise
It allows capturing rapid changes in signals
It lowers the resolution
It increases the measurement range
Explanation - High‑speed acquisition captures signals with fast transients accurately.
Correct answer is: It allows capturing rapid changes in signals
Q.96 Which of the following is a common method for measuring small currents without disturbing the circuit?
Using a high‑resistance shunt resistor
Using a low‑resistance shunt resistor
Using a high‑current ammeter
Using a voltage probe
Explanation - A high‑resistance shunt draws minimal current, preserving circuit operation while measuring small currents.
Correct answer is: Using a high‑resistance shunt resistor
Q.97 The 'signal-to-quantization noise ratio' (SQNR) is most relevant in:
Analog measurement systems
Digital measurement systems
Mechanical measurement systems
Thermal measurement systems
Explanation - SQNR compares signal magnitude to quantization noise introduced by digitization.
Correct answer is: Digital measurement systems
Q.98 A sensor that outputs a voltage proportional to the mass of an object placed on it is a ________ sensor.
Load cell
Temperature sensor
Pressure sensor
Accelerometer
Explanation - Load cells convert force or mass into an electrical signal.
Correct answer is: Load cell
Q.99 Which of the following describes 'noise rejection' in instrumentation?
The ability of the instrument to reject signal components outside the measurement band
The ability of the instrument to reject measurement errors due to temperature drift
The ability of the instrument to reject mechanical vibrations
The ability to reject any form of error
Explanation - Noise rejection typically refers to filtering out unwanted frequencies.
Correct answer is: The ability of the instrument to reject signal components outside the measurement band
Q.100 A 'bridge' measurement circuit is commonly used to measure:
Capacitance only
Resistance only
Temperature, pressure, and strain
Current only
Explanation - Bridge circuits (Wheatstone, Wheatstone, etc.) are versatile for various physical quantity measurements.
Correct answer is: Temperature, pressure, and strain
Q.101 Which of the following is a typical application of a 'piezoelectric' sensor?
Measuring temperature
Measuring pressure changes
Measuring magnetic fields
Measuring light intensity
Explanation - Piezoelectric sensors generate voltage when mechanically stressed, useful for pressure measurement.
Correct answer is: Measuring pressure changes
Q.102 The 'input dynamic range' of a measurement system is defined as:
The ratio of the maximum to minimum measurable values
The maximum measurement time
The minimum noise level
The number of digits displayed
Explanation - Dynamic range quantifies the span between the smallest and largest signals accurately measured.
Correct answer is: The ratio of the maximum to minimum measurable values
Q.103 A measurement instrument that can be calibrated against a traceable standard is said to have:
High repeatability
High resolution
Traceability
Low drift
Explanation - Traceability ensures measurements can be linked to recognized standards.
Correct answer is: Traceability
Q.104 Which of the following best describes 'sensitivity drift'?
Change in measurement sensitivity over time
Change in measurement sensitivity with temperature
Change in measurement sensitivity with humidity
All of the above
Explanation - Sensitivity drift can occur due to various environmental or time-based factors.
Correct answer is: All of the above
Q.105 The 'offset voltage' of an amplifier is the voltage at the output when the input is zero. This is an example of:
Random error
Bias error
Noise
Precision
Explanation - Offset voltage represents a systematic bias in the amplifier’s output.
Correct answer is: Bias error
Q.106 A sensor that uses a variable resistor whose resistance changes with humidity is a ________ sensor.
Capacitive
Resistive
Thermal
Piezoelectric
Explanation - Resistive humidity sensors change resistance as humidity varies.
Correct answer is: Resistive
Q.107 In a measurement system, which element is responsible for converting a physical quantity into an electrical signal?
Display
Controller
Transducer
Amplifier
Explanation - The transducer maps the physical phenomenon to an electrical output.
Correct answer is: Transducer
Q.108 The term 'measurement uncertainty' is often expressed as:
A single value
A range around the measured value
A percentage of the input
The maximum error
Explanation - Uncertainty is represented as a confidence interval, e.g., ±0.05 V.
Correct answer is: A range around the measured value
Q.109 In a four‑wire Kelvin connection, the voltage leads are connected to:
The input terminals of the source
The measurement points of the resistor
The current leads of the source
The ground of the instrument
Explanation - Voltage leads sense the voltage across the resistor without drawing current.
Correct answer is: The measurement points of the resistor
Q.110 A sensor that converts an acoustic pressure signal into an electrical voltage is a ________ sensor.
Accelerometer
Microphone
Pressure sensor
Temperature sensor
Explanation - Microphones convert sound pressure waves into electrical signals.
Correct answer is: Microphone
Q.111 The 'zero‑point error' in a measurement instrument is caused by:
Incorrect calibration
Temperature drift
Random noise
All of the above
Explanation - Zero‑point error arises when the instrument does not read zero when the input is zero.
Correct answer is: Incorrect calibration
Q.112 Which of the following is a characteristic of a 'digital voltmeter'?
Continuous needle movement
Quantized output display
Requires a separate ADC
Low input impedance
Explanation - Digital meters display discrete numerical values rather than continuous needle sweeps.
Correct answer is: Quantized output display
Q.113 Which type of measurement error is caused by the presence of a stray magnetic field near a sensor?
Thermal error
Electromagnetic interference
Calibration error
Mechanical error
Explanation - Stray magnetic fields introduce interference, affecting sensor outputs.
Correct answer is: Electromagnetic interference
Q.114 The 'noise floor' of a sensor is lowered by:
Increasing its input impedance
Adding shielding and filtering
Increasing the sampling rate
Using a higher resolution display
Explanation - Shielding and filtering reduce external noise contributions, lowering the noise floor.
Correct answer is: Adding shielding and filtering
Q.115 A 'strain‑gauge' is an example of a ________ sensor.
Pressure sensor
Temperature sensor
Mechanical deformation sensor
Electric field sensor
Explanation - Strain gauges detect changes in length or strain, measuring mechanical deformation.
Correct answer is: Mechanical deformation sensor
Q.116 Which of the following is the primary function of a 'gain stage' in signal conditioning?
Reduce the signal amplitude
Amplify the signal to match the input range of the ADC
Filter high‑frequency noise
Store the signal for later processing
Explanation - A gain stage adjusts signal levels to match the ADC’s input range for optimal resolution.
Correct answer is: Amplify the signal to match the input range of the ADC
Q.117 Which of the following best describes 'time delay' in a measurement system?
Delay in the signal itself
Delay in the processing of the measurement signal
Delay in the display of the measurement
All of the above
Explanation - Time delay can affect signal, processing, and display times in a measurement system.
Correct answer is: All of the above
Q.118 A 'temperature probe' that uses a thermopile to generate a voltage is an example of a ________ sensor.
Resistive
Capacitive
Thermoelectric
Optical
Explanation - Thermoelectric sensors generate voltage from temperature differences via the Seebeck effect.
Correct answer is: Thermoelectric
Q.119 The 'range' of a digital instrument is determined by:
Its maximum input voltage
Its resolution
Its input impedance
Its power supply voltage
Explanation - The range is the span of input values the instrument can handle accurately.
Correct answer is: Its maximum input voltage
Q.120 Which of the following is an advantage of using a 'differential probe'?
Higher input impedance
Lower common‑mode rejection ratio
Increased noise floor
Reduced measurement accuracy
Explanation - Differential probes typically have high input impedance and excellent common‑mode rejection.
Correct answer is: Higher input impedance
Q.121 A sensor that measures acceleration by changes in capacitance is known as an ________ sensor.
Capacitive accelerometer
Piezoelectric accelerometer
Force sensor
Temperature sensor
Explanation - Capacitive accelerometers detect acceleration via changes in capacitor plate spacing.
Correct answer is: Capacitive accelerometer
Q.122 The 'signal-to-noise ratio' (SNR) of a measurement system increases by:
Reducing the signal amplitude
Increasing the measurement bandwidth
Reducing noise power
Increasing the quantization noise
Explanation - Lowering noise improves the ratio of signal to noise.
Correct answer is: Reducing noise power
Q.123 A 'current shunt' used for measuring high currents typically has a resistance of:
Several ohms
Several kilohms
Less than a milliohm
More than ten ohms
Explanation - Low‑value shunts minimize voltage drop while allowing current measurement.
Correct answer is: Less than a milliohm
Q.124 In a measurement system, 'precision' is related to:
How close the measurement is to the true value
The reproducibility of repeated measurements
The maximum measurement range
The speed of measurement
Explanation - Precision refers to the consistency of repeated measurements.
Correct answer is: The reproducibility of repeated measurements
Q.125 The 'noise figure' of an amplifier is a measure of:
Its gain
Its bandwidth
The amount of noise added by the amplifier
Its linearity
Explanation - Noise figure quantifies how much noise the amplifier introduces relative to an ideal device.
Correct answer is: The amount of noise added by the amplifier
Q.126 Which of the following best defines a 'digital signal processing' (DSP) element in instrumentation?
Analog filtering
Digital filtering and computation
Mechanical amplification
Electrical isolation
Explanation - DSP applies algorithms to digital signals for filtering, transformation, etc.
Correct answer is: Digital filtering and computation
Q.127 A sensor that measures the concentration of gases in the air is a ________ sensor.
Thermocouple
Photoelectric
Gas sensor
Accelerometer
Explanation - Gas sensors detect specific gas species and concentrations.
Correct answer is: Gas sensor
Q.128 The 'maximum permissible error' (MPE) of a measurement instrument is defined as:
The maximum difference between measured and true value
The maximum measurement speed
The minimum detectable signal
The maximum number of digits displayed
Explanation - MPE represents the largest allowed error under specified conditions.
Correct answer is: The maximum difference between measured and true value
Q.129 A sensor that uses a piezoelectric crystal to generate a voltage in response to a pressure change is a ________ sensor.
Strain‑gauge
Pressure transducer
Temperature sensor
Capacitive sensor
Explanation - Piezoelectric crystals convert mechanical stress into voltage, commonly used in pressure transducers.
Correct answer is: Pressure transducer
Q.130 The 'time constant' of an RC filter determines:
The cutoff frequency
The input impedance
The measurement range
The noise figure
Explanation - Time constant τ = R·C determines the frequency at which the filter attenuates signals.
Correct answer is: The cutoff frequency
Q.131 Which of the following is a property of a 'capacitive sensor'?
Its output voltage is proportional to magnetic field
Its output changes with distance between plates
It is used to measure current
It is insensitive to temperature changes
Explanation - Capacitance varies with the distance between plates, allowing displacement or humidity sensing.
Correct answer is: Its output changes with distance between plates
Q.132 The 'input resistance' of a voltmeter should be:
Low to minimize loading
High to minimize loading
Equal to the circuit resistance
Zero
Explanation - High input resistance ensures the meter does not affect the measured voltage.
Correct answer is: High to minimize loading
Q.133 In a measurement system, which component is responsible for filtering out unwanted frequencies?
Amplifier
Integrator
Filter
Controller
Explanation - Filters remove unwanted frequency components from the signal.
Correct answer is: Filter
Q.134 The 'noise figure' of a sensor is minimized by:
Using a high‑value resistor
Using a low‑noise amplifier
Increasing the sampling rate
Using a larger sensor package
Explanation - Low‑noise amplifiers add minimal noise, reducing the sensor’s overall noise figure.
Correct answer is: Using a low‑noise amplifier
Q.135 Which of the following is the purpose of a 'temperature compensation circuit' in a measurement system?
To increase the measurement range
To correct the measurement for temperature effects
To provide power to the sensor
To amplify the signal
Explanation - Temperature compensation ensures measurement accuracy despite temperature variations.
Correct answer is: To correct the measurement for temperature effects
Q.136 A 'digital storage oscilloscope' can capture transient events because it uses a:
Continuous analog display
Memory buffer to store waveform samples
Single‑ended input only
Low‑pass filter only
Explanation - The buffer stores sampled data for post‑processing and display.
Correct answer is: Memory buffer to store waveform samples
Q.137 Which of the following is a typical application of a 'strain‑gauge bridge'?
Measuring temperature changes
Measuring electrical resistance
Measuring mechanical strain
Measuring light intensity
Explanation - Strain‑gauge bridges detect mechanical strain via changes in resistance.
Correct answer is: Measuring mechanical strain
Q.138 A 'voltage divider' used in a measurement circuit primarily functions to:
Amplify the input voltage
Reduce the input voltage to a measurable level
Provide a stable reference voltage
Increase measurement range
Explanation - A voltage divider scales down high voltages for safe measurement.
Correct answer is: Reduce the input voltage to a measurable level
Q.139 The 'maximum measurement time' of an ADC is determined by its:
Sampling rate
Resolution
Input range
Power supply voltage
Explanation - The sampling rate dictates how fast the ADC can acquire data.
Correct answer is: Sampling rate
Q.140 A sensor that uses a thermopile to generate a voltage proportional to temperature difference is a ________ sensor.
Thermoelectric sensor
Thermistor
Thermocouple
Capacitive sensor
Explanation - Thermoelectric sensors (thermopiles) produce voltage via the Seebeck effect.
Correct answer is: Thermoelectric sensor
Q.141 In measurement instrumentation, 'dynamic range' is usually expressed in:
Millivolts
Decibels
Ohms
Coulombs
Explanation - Dynamic range is commonly expressed in dB, indicating the ratio of max to min signals.
Correct answer is: Decibels
Q.142 The 'dead time' of a digital counter is the period after each count when it cannot register a new event. This is important in measuring:
High‑frequency signals
Low‑frequency signals
DC voltage
Temperature
Explanation - Dead time limits the maximum count rate for high‑frequency events.
Correct answer is: High‑frequency signals
Q.143 Which of the following best describes the function of a 'signal amplifier'?
To convert a physical quantity into a voltage
To increase the amplitude of a signal to match the ADC input range
To store data for later use
To provide power to the sensor
Explanation - The amplifier boosts small sensor outputs to a usable level for digital conversion.
Correct answer is: To increase the amplitude of a signal to match the ADC input range
Q.144 Which of the following is a key factor that determines the accuracy of a digital multimeter?
Display brightness
Input impedance
ADC resolution
Case material
Explanation - Higher ADC resolution allows finer measurement steps, improving accuracy.
Correct answer is: ADC resolution
Q.145 A sensor that measures the difference between two voltage levels is known as a ________ sensor.
Differential sensor
Absolute sensor
Analog sensor
Digital sensor
Explanation - Differential sensors output a signal proportional to the voltage difference between two nodes.
Correct answer is: Differential sensor
Q.146 Which of the following is a common source of 'offset error' in an instrumentation amplifier?
High input bias current
Temperature drift
Reference voltage drift
All of the above
Explanation - Offset error can arise from multiple sources including bias currents, temperature, and reference drift.
Correct answer is: All of the above
Q.147 In an instrumentation system, the 'input bandwidth' is defined as the range of frequencies over which the input signal is accurately amplified. It is limited by:
The amplifier’s gain‑bandwidth product
The input resistance
The sensor’s physical size
The display resolution
Explanation - Gain‑bandwidth product limits how much frequency range an amplifier can handle.
Correct answer is: The amplifier’s gain‑bandwidth product
Q.148 A 'digital thermometer' typically uses a ________ sensor to measure temperature.
Thermocouple
Thermistor
Resistive thermometer (RTD)
All of the above
Explanation - Digital thermometers can employ any of these temperature sensors.
Correct answer is: All of the above
Q.149 Which of the following is NOT a characteristic of a 'low‑noise amplifier'?
High gain
Low input noise
Low distortion
High power consumption
Explanation - Low‑noise amplifiers are typically designed for low power operation.
Correct answer is: High power consumption
Q.150 The 'measurement uncertainty' of an instrument is usually expressed as a ________.
Single value
Range (± value)
Percentage of full scale
Maximum error only
Explanation - Uncertainty is given as ± a certain value, representing a confidence interval.
Correct answer is: Range (± value)
Q.151 In a measurement system, 'bias' is often corrected by:
Adjusting the zero setting
Increasing the input voltage
Changing the measurement range
Adding more amplification
Explanation - Zeroing removes offset bias by calibrating the instrument to read zero when input is zero.
Correct answer is: Adjusting the zero setting
Q.152 Which of the following is a common type of 'data logger' used in environmental monitoring?
Temperature and humidity logger
Voltage logger
Current logger
Power logger
Explanation - Environmental data loggers record temperature and humidity over time.
Correct answer is: Temperature and humidity logger
Q.153 The 'gain' of an amplifier is defined as:
Output voltage divided by input voltage
Input voltage divided by output voltage
Output current divided by input current
Input current divided by output current
Explanation - Gain = Vout / Vin for voltage amplifiers.
Correct answer is: Output voltage divided by input voltage
Q.154 In a 'Wheatstone bridge', a small change in resistance causes:
A large output voltage change
No change in output voltage
A small output voltage change
A change in input current only
Explanation - Wheatstone bridges are highly sensitive to small resistance changes.
Correct answer is: A large output voltage change
Q.155 A sensor that detects the presence of a magnetic field by measuring the deflection of a charged particle is a ________ sensor.
Hall‑effect sensor
Thermocouple
Capacitive sensor
Thermistor
Explanation - Hall sensors use charged particle deflection to sense magnetic fields.
Correct answer is: Hall‑effect sensor
Q.156 In measurement instrumentation, which of the following best describes 'linearity error'?
Deviation from a straight‑line relationship between input and output
Error introduced by temperature drift
Error introduced by random noise
Error introduced by power supply fluctuations
Explanation - Linearity error measures how far the output deviates from ideal linearity.
Correct answer is: Deviation from a straight‑line relationship between input and output
Q.157 Which of the following is a typical application of a 'digital pressure sensor'?
Measuring atmospheric pressure
Measuring blood pressure
Measuring temperature
Measuring humidity
Explanation - Digital pressure sensors are used in medical devices to monitor blood pressure.
Correct answer is: Measuring blood pressure
Q.158 The 'resolution' of a digital scale that can display up to 2000 steps over a 5 kg range is:
0.0025 kg
0.005 kg
0.01 kg
0.025 kg
Explanation - Resolution = Full scale / Number of steps = 5 kg / 2000 = 0.0025 kg.
Correct answer is: 0.0025 kg
Q.159 Which of the following statements correctly describes the purpose of 'zero calibration' in a measurement instrument?
To set the instrument to read the maximum value
To eliminate offset error when measuring zero input
To calibrate the instrument for temperature changes
To ensure the instrument has high precision
Explanation - Zero calibration ensures the instrument reads zero when the input is zero.
Correct answer is: To eliminate offset error when measuring zero input
Q.160 In a measurement system, the 'input voltage range' of a digital multimeter is typically specified as:
A single fixed value
A minimum and maximum value
Only a maximum value
Only a minimum value
Explanation - The instrument can measure voltages between the specified min and max.
Correct answer is: A minimum and maximum value
Q.161 Which of the following is an example of a 'digital sensor'?
Thermocouple
Resistive temperature detector (RTD)
Optical encoder
Capacitive sensor
Explanation - Optical encoders provide digital output (binary) rather than analog voltage.
Correct answer is: Optical encoder