Q1. Which instrument is used to measure current?
A) Voltmeter
B) Ammeter
C) Wattmeter
D) Energy meter
Ans: B
Q2. Which instrument measures power in an AC circuit?
A) Ammeter
B) Voltmeter
C) Wattmeter
D) Multimeter
Ans: C
Q3. Which law is used in a potentiometer?
A) Kirchhoff’s law
B) Ohm’s law
C) Faraday’s law
D) Coulomb’s law
Ans: B
Q4. Which instrument measures energy consumption?
A) Wattmeter
B) Energy meter
C) Galvanometer
D) Voltmeter
Ans: B
Q5. Megger is used for measuring:
A) Low resistance
B) Medium resistance
C) High resistance
D) Current
Ans: C
Q6. The sensitivity of a galvanometer depends on:
A) Resistance of coil
B) Number of turns
C) Strength of magnet
D) All of the above
Ans: D
Q7. Which type of instrument can measure both AC and DC quantities?
A) Moving coil
B) Moving iron
C) Hot-wire
D) Dynamometer
Ans: B
Q8. In a PMMC instrument, the deflecting torque is proportional to:
A) Current
B) Voltage
C) Current²
D) Resistance
Ans: A
Q9. A dynamometer type wattmeter works on:
A) Magnetic induction
B) Electrostatic force
C) Interaction of fields
D) Heating effect
Ans: C
Q10. Creeping error is found in:
A) Voltmeter
B) Ammeter
C) Energy meter
D) Frequency meter
Ans: C
Q11. Which instrument is used for calibration of ammeter?
A) Potentiometer
B) Ohmmeter
C) Wattmeter
D) Energy meter
Ans: A
Q12. Which device is used to measure unknown frequency?
A) Voltmeter
B) Oscilloscope
C) Galvanometer
D) Frequency meter
Ans: D
Q13. An ideal voltmeter has:
A) Zero resistance
B) Infinite resistance
C) Medium resistance
D) None
Ans: B
Q14. An ideal ammeter has:
A) Zero resistance
B) Infinite resistance
C) Very high resistance
D) None
Ans: A
Q15. The function of a shunt in an ammeter is:
A) Reduce current
B) Increase resistance
C) Bypass extra current
D) Increase sensitivity
Ans: C
Q16. Which instrument is most suitable for measuring alternating current of any waveform?
A) PMMC
B) Moving iron
C) Electrostatic
D) Galvanometer
Ans: B
Q17. The torque required to keep pointer at zero position is:
A) Deflecting torque
B) Controlling torque
C) Damping torque
D) None
Ans: B
Q18. In induction type energy meter, braking torque is produced by:
A) Eddy currents
B) Friction
C) Spring
D) Magnet
Ans: A
Q19. The unit of electric energy is:
A) Watt
B) Joule
C) Watt-hour
D) Newton
Ans: C
Q20. Which of the following uses hot wire?
A) Voltmeter
B) Ammeter
C) Thermocouple meter
D) Hot-wire instrument
Ans: D
Q21. Lissajous figures are obtained on:
A) Ammeter
B) Voltmeter
C) CRO
D) Energy meter
Ans: C
Q22. Which instrument is suitable for measurement of radio frequency?
A) PMMC
B) Hot wire instrument
C) Galvanometer
D) Moving iron
Ans: B
Q23. Which method is best for measuring resistance of insulation?
A) Wheatstone bridge
B) Kelvin bridge
C) Megger
D) Potentiometer
Ans: C
Q24. Which instrument cannot be used for AC measurement?
A) PMMC
B) Moving iron
C) Hot wire
D) Dynamometer
Ans: A
Q25. Electrostatic voltmeter is used for:
A) Low voltage
B) High voltage
C) Current
D) Resistance
Ans: B
Q26. A wattmeter gives incorrect readings due to:
A) Pressure coil inductance
B) Current coil resistance
C) Both A & B
D) None
Ans: C
Q27. Standard resistor is used for measurement of:
A) Voltage
B) Power
C) Current
D) Resistance
Ans: C
Q28. The ratio of instrument resistance to the shunt resistance is called:
A) Multiplying factor
B) Shunt ratio
C) Swamping resistance
D) Resistance factor
Ans: B
Q29. Which device is used to measure power factor?
A) Wattmeter
B) Power factor meter
C) Energy meter
D) CRO
Ans: B
Q30. Which device measures phase difference?
A) Potentiometer
B) Oscilloscope
C) Power factor meter
D) Galvanometer
Ans: B
Q31. Kelvin bridge is used for measurement of:
A) High resistance
B) Low resistance
C) Medium resistance
D) Inductance
Ans: B
Q32. Which instrument is used for accurate measurement of unknown emf?
A) Potentiometer
B) Voltmeter
C) Ammeter
D) Galvanometer
Ans: A
Q33. Which instrument is most accurate for DC measurement?
A) PMMC
B) MI instrument
C) Hot wire
D) Dynamometer
Ans: A
Q34. Which meter is most widely used in households?
A) Ammeter
B) Energy meter
C) Wattmeter
D) Voltmeter
Ans: B
Q35. The controlling torque in PMMC instruments is provided by:
A) Gravity control
B) Spring control
C) Damping control
D) Eddy currents
Ans: B
Q36. Hay’s bridge is used for measurement of:
A) Capacitance
B) Inductance (high Q)
C) Resistance
D) Frequency
Ans: B
Q37. Maxwell’s bridge measures:
A) Low resistance
B) Capacitance
C) Inductance (low Q)
D) Frequency
Ans: C
Q38. Anderson’s bridge measures:
A) Capacitance
B) Inductance
C) Resistance
D) Frequency
Ans: B
Q39. Schering bridge is used for measurement of:
A) Resistance
B) Inductance
C) Capacitance & dielectric loss
D) Frequency
Ans: C
Q40. Which meter works on induction principle?
A) Wattmeter
B) Energy meter
C) Ammeter
D) Voltmeter
Ans: B
Q41. Ballistic galvanometer is used to measure:
A) Steady current
B) Charge
C) Resistance
D) Power
Ans: B
Q42. A CRO can measure:
A) Voltage
B) Frequency
C) Phase angle
D) All of the above
Ans: D
Q43. In an energy meter, braking magnet is made of:
A) Permanent magnet
B) Electromagnet
C) Soft iron
D) Copper
Ans: A
Q44. Which type of error occurs due to change in temperature?
A) Instrumental
B) Environmental
C) Observational
D) Gross
Ans: B
Q45. Dead time of instrument is:
A) Initial delay
B) Time to reach final value
C) Time to start response
D) None
Ans: A
Q46. Range of instrument is extended by:
A) Shunt
B) Multiplier
C) Both A & B
D) None
Ans: C
Q47. Which bridge measures frequency?
A) Wien’s bridge
B) Maxwell’s bridge
C) Kelvin bridge
D) Schering bridge
Ans: A
Q48. Which device compares two nearly equal voltages?
A) Voltmeter
B) Potentiometer
C) Galvanometer
D) CRO
Ans: B
Q49. Which type of error is due to improper adjustment of instrument?
A) Gross error
B) Systematic error
C) Random error
D) Parallax error
Ans: B
Q50. The power factor of a purely resistive circuit is:
A) 0
B) 1
C) Lagging
D) Leading
Ans: B
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