1. The instrument used to measure current is called a:
(A) Voltmeter
(B) Ammeter
(C) Wattmeter
(D) Ohmmeter
2. The unit of resistance is:
(A) Farad
(B) Henry
(C) Ohm
(D) Volt
3. A voltmeter is always connected:
(A) In series with circuit
(B) In parallel with circuit
(C) Across battery only
(D) Across ground
4. A galvanometer is a device used to detect:
(A) Current direction
(B) Voltage only
(C) Magnetic field
(D) Temperature
5. The sensitivity of a galvanometer is increased by:
(A) Using thicker wire
(B) Decreasing magnetic field
(C) Increasing coil resistance
(D) Increasing number of turns
6. Which instrument measures power in an electrical circuit?
(A) Ammeter
(B) Voltmeter
(C) Wattmeter
(D) Energy meter
7. The moving coil instrument can measure:
(A) DC only
(B) AC only
(C) Both AC and DC
(D) Frequency
8. The moving iron instrument can measure:
(A) Resistance
(B) Only DC
(C) Only AC
(D) AC and DC
9. The torque that moves the pointer of an analog instrument is called:
(A) Controlling torque
(B) Deflecting torque
(C) Damping torque
(D) Restoring torque
10. The controlling torque in a PMMC instrument is provided by:
(A) Spiral springs
(B) Gravity
(C) Damping fluid
(D) Friction
11. The damping torque in an instrument helps to:
(A) Increase accuracy
(B) Increase pointer deflection
(C) Decrease sensitivity
(D) Stop oscillations quickly
12. The instrument used to measure electrical energy is:
(A) Wattmeter
(B) Energy meter
(C) Potentiometer
(D) Oscilloscope
13. In a wattmeter, the current coil is connected in:
(A) Series with load
(B) Parallel with load
(C) Across supply
(D) Across shunt
14. The voltage coil of a wattmeter is connected in:
(A) In open circuit
(B) Series with load
(C) Parallel with load
(D) Across resistor only
15. The basic principle of operation of an ammeter is:
(A) Magnetic effect of current
(B) Chemical effect
(C) Thermal effect
(D) Inductive effect
16. The range of an ammeter can be extended using:
(A) Multiplier resistor
(B) Shunt resistor
(C) Transformer
(D) Rheostat
17. The range of a voltmeter can be extended by using:
(A) Transformer
(B) Shunt resistor
(C) Series coil
(D) Multiplier resistor
18. The internal resistance of an ammeter is:
(A) Very low
(B) Very high
(C) Infinite
(D) Medium
19. The internal resistance of a voltmeter is:
(A) Zero
(B) Very low
(C) Very high
(D) Infinite
20. A megger is used to measure:
(A) Power
(B) Low resistance
(C) Voltage
(D) High resistance
21. Ohm’s law states that:
(A) V = IR
(B) V = I/R
(C) I = VR
(D) P = VI²
22. A wattmeter measures:
(A) Apparent power
(B) Active power
(C) Reactive power
(D) Total energy
23. The working principle of an energy meter is based on:
(A) Heating effect
(B) Magnetic repulsion
(C) Electrostatic force
(D) Electromagnetic induction
24. The unit of energy is:
(A) Joule per second
(B) Ampere-hour
(C) Watt-hour
(D) Volt per ampere
25. The instrument which measures the phase difference between voltage and current is:
(A) Wattmeter
(B) Power factor meter
(C) Frequency meter
(D) Voltmeter
26. The standard resistor is used for:
(A) Protection
(B) Reducing resistance
(C) Increasing current
(D) Calibration of instruments
27. A thermocouple measures:
(A) Temperature
(B) Pressure
(C) Resistance
(D) Capacitance
28. The instrument used to display waveform of voltage is:
(A) Oscilloscope
(B) Multimeter
(C) Wattmeter
(D) Frequency meter
29. The frequency of an AC signal is measured using:
(A) Galvanometer
(B) Wattmeter
(C) Ammeter
(D) Frequency meter
30. In a dynamometer type wattmeter, both coils are:
(A) Iron-cored
(B) Air-cored
(C) Laminated
(D) Wound on same core
31. The ratio of deflecting torque to controlling torque is proportional to:
(A) Pointer deflection
(B) Damping
(C) Accuracy
(D) Power factor
32. An ohmmeter measures:
(A) Resistance
(B) Voltage
(C) Current
(D) Power
33. A digital multimeter can measure:
(A) Only current
(B) Only voltage
(C) Voltage, current, and resistance
(D) Only resistance
34. The instrument used for calibration of AC instruments is:
(A) Voltmeter
(B) Potentiometer
(C) Energy meter
(D) Galvanometer
35. The deflection of the pointer in an instrument is proportional to:
(A) Frequency
(B) Current squared
(C) Voltage
(D) Deflecting torque
36. The damping provided by air friction is used in:
(A) PMMC instrument
(B) Hot-wire instrument
(C) Moving iron instrument
(D) Electrostatic instrument
37. A hot-wire ammeter works on the principle of:
(A) Chemical effect
(B) Magnetic effect
(C) Induction
(D) Heating effect of current
38. A dynamometer type wattmeter can measure:
(A) Both AC and DC power
(B) Only DC power
(C) Only AC power
(D) Reactive power
39. The permanent magnet moving coil (PMMC) instrument uses:
(A) Steel coil
(B) Soft iron core
(C) Electromagnet
(D) Rectangular coil and permanent magnet
40. A Weston type frequency meter is based on:
(A) Magnetic resonance
(B) Electrical resonance
(C) Thermal expansion
(D) Capacitive coupling
41. A synchroscope is used to:
(A) Check phase synchronization
(B) Measure resistance
(C) Measure torque
(D) Measure current
42. The main error in PMMC instruments is due to:
(A) Load change
(B) Frequency variation
(C) Temperature variation
(D) Power factor
43. The scale of PMMC instrument is:
(A) Linear up to half scale
(B) Non-uniform
(C) Logarithmic
(D) Uniform
44. The scale of moving iron instrument is:
(A) Uniform
(B) Non-uniform
(C) Linear
(D) Exponential
45. The torque in an induction-type energy meter is proportional to:
(A) Power
(B) Voltage
(C) Current squared
(D) Frequency
46. The working principle of a potentiometer is based on:
(A) Comparison of unknown voltage with known voltage
(B) Induction
(C) Capacitance
(D) Magnetic flux
47. The zero adjustment of analog instruments is done by:
(A) Magnetic shunt
(B) Electrical screw
(C) Rheostat
(D) Mechanical screw
48. A ballistic galvanometer measures:
(A) Quantity of charge
(B) Steady current
(C) Voltage
(D) Power
49. The instrument which measures reactive power in AC circuit is:
(A) Wattmeter
(B) Var meter
(C) Power factor meter
(D) Frequency meter
50. In an energy meter, the rotating aluminum disc rotates due to:
(A) Resistance heating
(B) Magnetic flux leakage
(C) Armature reaction
(D) Eddy currents