ELECTRICAL AND ELECTRONIC MEASUREMENTS MCQs

 

ELECTRICAL AND ELECTRONIC MEASUREMENTS MCQs

Q1. The basic principle of a moving coil instrument is based on
A) Electromagnetic induction
B) Motor principle
C) Heating effect
D) Chemical effect
Answer: B

Q2. In a permanent magnet moving coil (PMMC) instrument, the deflection is proportional to
A) Current
B) Voltage
C) Power
D) Frequency
Answer: A

Q3. An instrument which measures the RMS value of AC current is called
A) Average responding instrument
B) True RMS instrument
C) Peak responding instrument
D) Moving coil instrument
Answer: B

Q4. The controlling torque in a PMMC instrument is provided by
A) Spring
B) Gravity
C) Eddy current
D) Air friction
Answer: A

Q5. The damping torque in a moving iron instrument is due to
A) Air friction
B) Eddy currents
C) Spring control
D) Gravity
Answer: A

Q6. The unit of sensitivity of a galvanometer is
A) A/radian
B) radian/A
C) A/V
D) V/A
Answer: B

Q7. A wattmeter measures
A) Apparent power
B) Active power
C) Reactive power
D) Average voltage
Answer: B

Q8. In an electrodynamometer type wattmeter, the fixed coil is called
A) Pressure coil
B) Current coil
C) Voltage coil
D) None
Answer: B

Q9. The range of an ammeter can be extended using
A) Multiplier
B) Shunt
C) Capacitor
D) Transformer
Answer: B

Q10. The range of a voltmeter can be extended by using
A) Multiplier resistor
B) Shunt resistor
C) Capacitor
D) Inductor
Answer: A

Q11. A potentiometer is used for
A) Measuring high voltage
B) Measuring small EMF accurately
C) Measuring current
D) Measuring resistance
Answer: B

Q12. The working principle of a thermocouple is
A) Joule heating
B) Seebeck effect
C) Faraday’s law
D) Lenz’s law
Answer: B

Q13. The moving iron instruments can be used for
A) DC only
B) AC only
C) Both AC and DC
D) None
Answer: C

Q14. In a PMMC instrument, the damping is provided by
A) Eddy currents in the aluminum former
B) Air friction
C) Spring
D) Pointer friction
Answer: A

Q15. A CRO is used to measure
A) Only DC signals
B) Only AC signals
C) Both AC and DC waveforms
D) None
Answer: C

Q16. The main advantage of an electronic voltmeter is
A) High sensitivity and input impedance
B) Low cost
C) Ruggedness
D) Mechanical damping
Answer: A

Q17. A digital voltmeter displays readings in
A) Analog form
B) Digital form
C) Both
D) None
Answer: B

Q18. The basic function of the ADC in a digital instrument is
A) Amplification
B) Conversion of analog to digital signal
C) Integration
D) Multiplication
Answer: B

Q19. The least count of an instrument is
A) The smallest value it can measure
B) The largest value
C) The mean value
D) The error
Answer: A

Q20. An instrument which measures without any contact is known as
A) Digital instrument
B) Null type instrument
C) Non-contact type instrument
D) Analog instrument
Answer: C

Q21. An energy meter measures
A) Instantaneous power
B) Energy consumed
C) Power factor
D) Voltage
Answer: B

Q22. Creeping in energy meters is due to
A) Overvoltage
B) Vibration
C) Excess friction
D) Overcompensation for friction
Answer: D

Q23. The instrument used for phase angle measurement is
A) Wattmeter
B) Energy meter
C) Power factor meter
D) Frequency meter
Answer: C

Q24. A Wien bridge is used for measuring
A) Resistance
B) Inductance
C) Capacitance and frequency
D) Voltage
Answer: C

Q25. The Kelvin double bridge is used for measurement of
A) High resistance
B) Low resistance
C) Capacitance
D) Frequency
Answer: B

Q26. In a CRO, the time base generator produces
A) Sawtooth waveform
B) Square waveform
C) Sine waveform
D) Triangular waveform
Answer: A

Q27. Lissajous figures on a CRO are used to measure
A) Frequency and phase difference
B) Current
C) Power
D) Voltage
Answer: A

Q28. In digital instruments, noise immunity is
A) High
B) Low
C) Zero
D) Moderate
Answer: A

Q29. An ohmmeter measures
A) Voltage
B) Resistance
C) Capacitance
D) Current
Answer: B

Q30. A megger is used for measuring
A) Low resistance
B) High resistance
C) Capacitance
D) Inductance
Answer: B

Q31. A Q-meter is used for measurement of
A) Quality factor of a coil
B) Power
C) Capacitance
D) Resistance
Answer: A

Q32. The term “accuracy” of an instrument represents
A) Closeness to true value
B) Repeatability
C) Precision
D) Resolution
Answer: A

Q33. The error due to temperature variation in a resistor is
A) Random error
B) Gross error
C) Systematic error
D) None
Answer: C

Q34. In a bridge circuit, balance condition is independent of
A) Source voltage
B) Frequency
C) Capacitance
D) Inductance
Answer: A

Q35. The deflection type instruments are
A) Potentiometer
B) Galvanometer
C) Null type
D) Bridge circuit
Answer: B

Q36. The calibration of a voltmeter is done by
A) Standard potentiometer
B) Ammeter
C) Wattmeter
D) Energy meter
Answer: A

Q37. Frequency of AC can be measured by
A) Weston frequency meter
B) Energy meter
C) Megger
D) CRO only
Answer: A

Q38. A digital multimeter can measure
A) Only voltage
B) Only current
C) Voltage, current, resistance
D) Frequency only
Answer: C

Q39. A ballistic galvanometer measures
A) Steady current
B) Charge
C) Voltage
D) Power
Answer: B

Q40. The loading effect of an instrument is due to
A) Finite input impedance
B) Infinite input impedance
C) Zero input impedance
D) Output impedance
Answer: A

Q41. An integrating type digital voltmeter uses
A) ADC
B) DAC
C) Op-amp
D) Integrator
Answer: D

Q42. The sensitivity of a voltmeter increases with
A) Increase in resistance
B) Decrease in resistance
C) Increase in current
D) Decrease in voltage
Answer: A

Q43. The frequency range of audio frequency voltmeter is typically
A) 20 Hz – 20 kHz
B) 20 Hz – 200 Hz
C) 200 Hz – 20 MHz
D) 2 Hz – 200 kHz
Answer: A

Q44. The standard resistor used in calibration is made of
A) Manganin
B) Copper
C) Aluminum
D) Iron
Answer: A

Q45. The function of a current transformer is to
A) Step up current
B) Step down current for measurement
C) Step up voltage
D) Step down voltage
Answer: B

Q46. The core of an instrument transformer is made of
A) Silicon steel
B) Soft iron
C) Hard steel
D) Copper
Answer: A

Q47. The purpose of a potential transformer is to
A) Measure high current
B) Step down voltage for measurement
C) Step up voltage
D) Measure resistance
Answer: B

Q48. An ideal instrument should have
A) Infinite accuracy
B) Infinite sensitivity and zero error
C) Infinite damping
D) Finite deflection
Answer: B

Q49. The input impedance of an ideal voltmeter is
A) Infinite
B) Zero
C) High but finite
D) Medium
Answer: A

Q50. The output impedance of an ideal ammeter is
A) Infinite
B) Zero
C) Very high
D) Medium
Answer: B