What is the primary function of a transducer?
A To amplify signals
B To convert physical quantities into electrical signals
C To store energy
D To measure current
Transducers convert physical parameters like temperature, pressure, or displacement into electrical signals for measurement and control.
Which device is used to measure the power factor of an electrical circuit?
A Wattmeter
B Power factor meter
C Frequency meter
D Ammeter
Power factor meters are specialized instruments used to measure the ratio of real power to apparent power in AC circuits.
What is the principle of operation of an induction-type energy meter?
A Electromagnetic induction
B Piezoelectric effect
C Electrostatic force
D Thermal expansion
Induction-type energy meters work on the principle of electromagnetic induction, where a rotating disc moves proportionally to power consumption.
What is the purpose of using a strain gauge?
A To measure displacement
B To measure strain in materials
C To measure temperature
D To measure pressure
Strain gauges detect changes in resistance caused by strain in materials, allowing for precise measurement of deformation.
What does a signal conditioner do in a measurement system?
A Amplifies and filters the signal
B Measures the signal directly
C Converts analog signals to digital
D Stores the signal
Signal conditioners prepare raw signals from transducers by amplifying, filtering, or converting them into usable forms.
Which instrument is used to detect phase difference between two AC signals?
A Phase meter
B Frequency meter
C Oscilloscope
D Voltmeter
Phase meters measure the angular phase difference between two alternating signals in AC circuits.
What is the primary function of a data acquisition system?
A To store electrical energy
B To collect and process data from sensors
C To measure voltage only
D To transmit data wirelessly
Data acquisition systems gather electrical signals from sensors, process them, and store or display the information.
What type of bridge is used to measure inductance?
A Maxwell’s bridge
B Wheatstone bridge
C Kelvin bridge
D Schering bridge
Maxwell’s bridge is used to measure the inductance of an inductor by balancing the bridge using standard components.
Which transducer is used for measuring temperature?
A LVDT
B Thermocouple
C Strain gauge
D Piezoelectric sensor
A thermocouple generates a voltage proportional to the temperature difference between its two junctions.
What is the unit of power measured by a wattmeter?
A Amperes
B Watts
C Volts
D Ohms
Wattmeters measure power in watts, which is the product of voltage and current multiplied by the power factor.
Which material is commonly used in piezoelectric transducers?
A Quartz
B Copper
C Iron
D Aluminum
Quartz exhibits the piezoelectric effect, where mechanical stress generates an electrical charge, making it ideal for sensors.
What does an oscilloscope primarily measure?
A Resistance
B Voltage variations over time
C Power
D Capacitance
Oscilloscopes display the waveform of electrical signals, allowing analysis of voltage changes over time.
What is the dynamic characteristic of an instrument?
A Linearity
B Time constant
C Accuracy
D Sensitivity
The dynamic characteristic of an instrument describes how quickly it responds to changes, with the time constant indicating response speed.
Which type of noise is reduced by using shielding in electrical systems?
A Thermal noise
B Electromagnetic interference (EMI)
C Shot noise
D Flicker noise
Shielding protects signals from external electromagnetic fields, reducing noise and improving accuracy.
What is the purpose of calibration in instruments?
A To increase range
B To ensure accuracy by comparing with a standard
C To reduce power consumption
D To increase response time
Calibration ensures that instruments provide accurate measurements by aligning their readings with reference standards.
Which instrument is primarily used to detect small currents?
A Ammeter
B Galvanometer
C Multimeter
D Wattmeter
Galvanometers are highly sensitive instruments used to detect and measure small currents in circuits.
What is the primary function of a potential transformer?
A To step down voltage for safe measurement
B To measure current
C To amplify signals
D To store energy
Potential transformers reduce high voltage to a measurable level for instruments like voltmeters.
Which type of meter measures the total energy consumption over time?
A Wattmeter
B Energy meter
C Multimeter
D Ammeter
Energy meters record the total energy consumed in a circuit, typically expressed in kilowatt-hours (kWh).
What is the unit of power measured by a wattmeter?
A Amperes
B Watts
C Volts
D Ohms
Wattmeters measure power in watts, which is the product of voltage and current multiplied by the power factor.
What is the purpose of using a Venturi meter?
A To measure pressure
B To measure flow rate of fluids
C To measure temperature
D To measure speed
Venturi meters measure the flow rate by detecting pressure differences across a constriction in the pipe.