Part XIII — Full-Length Mock Tests

Chapter 14: Full-Length Mock Test 1 — RRB JE CBT 2 Technical Abilities Pattern (100 MCQs)

Section A: Circuit Fundamentals and AC/DC Basics (20 Questions)

1. Ohm's Law is valid provided:
   (a) Temperature and other physical conditions remain constant (b) Only at absolute zero temperature (c) Only for AC circuits, never DC (d) Only for superconductors
2. The unit of electrical resistance is the:
   (a) Ohm (b) Farad (c) Henry (d) Weber
3. The unit of electrical capacitance is the:
   (a) Farad (b) Ohm (c) Henry (d) Tesla
4. The unit of electrical inductance is the:
   (a) Henry (b) Farad (c) Ohm (d) Weber
5. Electrical power in a DC circuit is given by:
   (a) P = VI (b) P = V/I (c) P = I/V (d) P = V + I
6. In an AC circuit with a pure resistor, voltage and current are:
   (a) In phase with each other (b) 90 degrees out of phase (c) 180 degrees out of phase (d) Always at a random, undefined phase difference
7. In an AC circuit with a pure inductor, current:
   (a) Lags voltage by 90 degrees (b) Leads voltage by 90 degrees (c) Is exactly in phase with voltage (d) Is always zero regardless of voltage
8. In an AC circuit with a pure capacitor, current:
   (a) Leads voltage by 90 degrees (b) Lags voltage by 90 degrees (c) Is exactly in phase with voltage (d) Is always zero regardless of voltage
9. Inductive reactance (XL) is given by:
   (a) 2πfL (b) 1/(2πfC) (c) R (d) 2πfC
10. Capacitive reactance (XC) is given by:
    (a) 1/(2πfC) (b) 2πfL (c) R (d) 2πfL×C
11. In a series RLC circuit, resonance occurs when:
    (a) XL equals XC (b) R equals zero always (c) XL is always much greater than XC (d) XC is always much greater than XL
12. At resonance in a series RLC circuit, the circuit's impedance is:
    (a) At its minimum value, equal to R (b) At its maximum possible value (c) Always zero regardless of R (d) Always infinite regardless of R
13. Impedance (Z) in an AC circuit is the vector combination of:
    (a) Resistance and reactance (b) Only resistance, with no reactance component (c) Only capacitance, with no resistance (d) Only inductance, with no resistance
14. Active power in an AC circuit is measured in:
    (a) Watts (b) VAR (c) VA (d) Ohms
15. Reactive power in an AC circuit is measured in:
    (a) VAR (b) Watts (c) Ohms (d) Henries
16. Apparent power in an AC circuit is measured in:
    (a) VA (b) Watts exclusively (c) VAR exclusively (d) Ohms
17. The relationship between apparent power (S), active power (P), and reactive power (Q) is:
    (a) S² = P² + Q² (b) S = P + Q always (c) S = P − Q always (d) S = P × Q always
18. A three-phase balanced star-connected system has line voltage related to phase voltage by:
    (a) VL = √3 × Vph (b) VL = Vph (c) VL = 3 × Vph (d) VL = Vph/√3
19. A three-phase balanced delta-connected system has line current related to phase current by:
    (a) IL = √3 × Iph (b) IL = Iph (c) IL = 3 × Iph (d) IL = Iph/√3
20. The power in a balanced three-phase circuit is given by:
    (a) √3 × VL × IL × cos φ (b) VL × IL only, with no power factor term (c) VL × IL × 3 always (d) VL/IL × cos φ

Section B: Electrical Machines (20 Questions)

21. A DC generator's EMF equation relates EMF to flux, speed, and:
    (a) The number of armature conductors/poles/parallel paths (b) Only the machine's physical colour (c) Only the machine's weight (d) Only the ambient temperature
22. A compound DC motor combines features of:
    (a) Both series and shunt field windings (b) Only a series field winding (c) Only a shunt field winding (d) No field winding at all
23. Commutator action in a DC machine primarily serves to:
    (a) Convert AC induced in the armature to DC output (in a generator) or vice versa (in a motor) (b) Increase the machine's physical size (c) Serve only a decorative function (d) Eliminate the need for any armature winding
24. A three-phase induction motor's starting torque, compared to its running torque behaviour, is generally:
    (a) Lower than its maximum (breakdown) torque (b) Always exactly equal to its breakdown torque (c) Always higher than its breakdown torque (d) Completely unrelated to running conditions
25. A "squirrel cage" induction motor rotor is characterised by:
    (a) Conducting bars short-circuited by end rings, with no external rotor connection (b) Wound rotor windings brought out via slip rings (c) A permanent magnet rotor (d) No rotor conductors at all
26. A "slip-ring" (wound-rotor) induction motor allows:
    (a) External resistance to be added to the rotor circuit for starting/speed control (b) No external rotor connection whatsoever (c) Operation only as a generator, never as a motor (d) Operation only at exactly synchronous speed
27. Starting torque of a wound-rotor induction motor can be improved by:
    (a) Adding external resistance in the rotor circuit (b) Removing all rotor resistance entirely (c) Disconnecting the stator supply (d) Reversing only one phase permanently
28. An auto-transformer starter for an induction motor is used primarily to:
    (a) Reduce starting current by applying reduced voltage at start (b) Increase starting current deliberately (c) Eliminate the need for any starting method (d) Convert the motor to DC operation
29. A star-delta starter reduces starting current by initially connecting the motor windings in:
    (a) Star, then switching to delta for normal running (b) Delta, then switching to star for normal running (c) Neither configuration, only a direct-on-line connection (d) A configuration unrelated to star or delta
30. The synchronous speed of a 4-pole, 50 Hz induction motor is:
    (a) 1500 rpm (b) 3000 rpm (c) 750 rpm (d) 1000 rpm
31. An alternator's voltage regulation is defined in relation to changes between:
    (a) No-load and full-load terminal voltage (b) Only the machine's physical dimensions (c) Only ambient humidity levels (d) Only the machine's paint colour
32. Parallel operation of alternators (synchronising) requires matching of:
    (a) Voltage magnitude, frequency, and phase sequence (b) Only physical size (c) Only manufacturer brand (d) Only colour of the machine casing
33. A stepper motor is characterised by:
    (a) Rotating in discrete steps in response to input pulses (b) Continuous, non-discrete rotation only, identical to a standard induction motor (c) Operation exclusively on three-phase AC supply (d) No practical control application
34. A servo motor is commonly used in applications requiring:
    (a) Precise position/speed control with feedback (b) Only constant, uncontrolled speed with no feedback (c) Only very large industrial fans (d) Only household lighting
35. A single-phase induction motor, unlike a three-phase induction motor, is generally:
    (a) Not self-starting without an auxiliary starting method (b) Always self-starting with no auxiliary method needed (c) Incapable of running at all (d) Usable only as a generator, never as a motor
36. A "capacitor-start" single-phase induction motor uses a capacitor primarily to:
    (a) Create a phase difference between winding currents to produce starting torque (b) Increase the running speed indefinitely (c) Eliminate the need for a starting winding (d) Convert the motor to three-phase operation
37. A universal motor can operate on:
    (a) Both AC and DC supply (b) Only three-phase AC supply (c) Only extra-high-voltage DC (d) Only battery-based supply with no AC capability
38. Which type of motor is commonly used in household mixers/vacuum cleaners, valued for high speed and compact size?
    (a) Universal motor (b) Large synchronous motor (c) Three-phase induction motor exclusively (d) Stepper motor exclusively
39. A transformer's "no-load test" (open-circuit test) is primarily used to determine:
    (a) Core/iron losses (b) Copper losses exclusively (c) Only the transformer's physical weight (d) Only the transformer's paint colour
40. A transformer's "short-circuit test" is primarily used to determine:
    (a) Copper losses and equivalent impedance (b) Core/iron losses exclusively (c) Only the transformer's physical size (d) Only the transformer's efficiency at no load

Section C: Power Systems and Protection (20 Questions)

41. The main function of a power station's generator transformer is to:
    (a) Step up generated voltage for efficient transmission (b) Step down transmission voltage for household use exclusively (c) Convert AC to DC (d) Convert DC to AC
42. A substation typically performs functions such as:
    (a) Voltage transformation and switching/protection of power circuits (b) Only decorative landscaping around transmission towers (c) Only billing of household consumers (d) Only manufacturing of new transformers
43. Corona loss on a transmission line becomes more significant at:
    (a) Higher transmission voltages (b) Only very low voltages (c) Only DC transmission, never AC (d) Only underground cable systems, never overhead lines
44. A "string insulator" used on transmission towers is primarily used to:
    (a) Support and insulate the conductor from the tower structure (b) Generate additional power (c) Serve only a decorative function (d) Replace the need for any conductor
45. "Sag" in an overhead transmission line conductor refers to:
    (a) The vertical difference between the level of supports and the lowest point of the conductor (b) The conductor's total length only (c) The conductor's electrical resistance only (d) The conductor's colour
46. Skin effect in AC conductors refers to the tendency of current to:
    (a) Concentrate near the conductor's surface at higher frequencies (b) Flow uniformly through the entire cross-section regardless of frequency (c) Flow only through the conductor's exact centre (d) Flow only in DC circuits, never AC
47. A ring main distribution system, compared to a radial system, generally offers:
    (a) Improved reliability, since a fault can be isolated while still supplying consumers from the other direction (b) Lower reliability with no redundancy (c) No practical difference in reliability (d) Use exclusively for extra-high-voltage transmission
48. Load factor in a power system is defined as the ratio of:
    (a) Average load to maximum (peak) load (b) Peak load to average load (c) Connected load to average load only (d) Installed capacity to connected load only
49. A high load factor generally indicates:
    (a) More uniform loading, better utilisation of generating capacity (b) Highly variable, peaky loading with poor utilisation (c) No relevance to generating capacity utilisation (d) Always a fault condition in the system
50. Demand factor is defined as the ratio of:
    (a) Maximum demand to total connected load (b) Total connected load to maximum demand (c) Average load to peak load (d) Peak load to installed capacity only
51. A "grid" in a power system refers to:
    (a) An interconnected network of generating stations and transmission lines (b) A single isolated generating station with no interconnection (c) Only a household wiring diagram (d) Only a single distribution transformer
52. Interconnection of regional power grids in India primarily allows:
    (a) Sharing of surplus power and improved overall reliability (b) Complete isolation of each region with no benefit (c) Only increased transmission losses with no other effect (d) Only increased cost with no reliability benefit
53. Which of the following is a common cause of transmission line faults?
    (a) Lightning strikes and insulator failure (b) Only routine, planned maintenance switching (c) Only excessively low ambient temperature with no other cause (d) Only excessive vegetation clearance, i.e., too much clearance
54. A "single-line-to-ground" fault is generally considered:
    (a) The most common type of transmission line fault (b) Impossible under any real-world condition (c) Always less severe than a three-phase fault, in terms of fault current magnitude (d) Unrelated to any protection scheme
55. A "three-phase fault," though less frequent, is generally considered:
    (a) The most severe type of fault in terms of fault current magnitude (b) The least severe type of fault (c) Impossible on any real transmission system (d) Identical in severity to an open-circuit condition
56. Reactive power compensation using shunt capacitor banks in a distribution system primarily helps to:
    (a) Improve voltage profile and reduce losses (b) Increase system losses deliberately (c) Reduce voltage at all points in the system (d) Serve no practical electrical function
57. A "tap-changer" on a power transformer allows:
    (a) Adjustment of the transformer's turns ratio to regulate output voltage (b) Complete disconnection of the transformer from the supply only (c) Conversion of AC to DC (d) Direct measurement of load current only
58. An "on-load tap changer" (OLTC), compared to an off-load tap changer, allows tap changes:
    (a) While the transformer remains energised and carrying load (b) Only when the transformer is completely de-energised (c) Only once during the transformer's entire service life (d) Only manually with no automatic operation ever possible
59. Power system stability broadly refers to a system's ability to:
    (a) Maintain synchronism and return to a stable operating condition after a disturbance (b) Always operate at exactly zero load (c) Never experience any disturbance whatsoever (d) Operate only in isolated, non-interconnected mode
60. Which of the following best describes the general trend in modern Indian power systems regarding renewable energy integration?
    (a) Increasing integration of solar/wind generation into the grid (b) Complete exclusion of any renewable source from the grid (c) Reliance solely on nuclear power with no other source (d) No change in the generation mix over recent years

Section D: Measurements, Electronics, Control, and Power Electronics (20 Questions)

61. A Wheatstone bridge is primarily used to measure:
    (a) Unknown resistance with high accuracy (b) Frequency directly (c) Only capacitance, never resistance (d) Only inductance, never resistance
62. A CRO (Cathode Ray Oscilloscope) is primarily used to:
    (a) Visually display and measure waveforms (b) Measure only DC resistance (c) Measure only mechanical vibration (d) Generate electrical power
63. A current transformer (CT) is used to:
    (a) Step down high current to a measurable low value for instruments/relays (b) Step up voltage for transmission (c) Convert AC to DC (d) Convert DC to AC
64. A potential transformer (PT), similar in concept to a CT, is used to:
    (a) Step down high voltage to a measurable low value for instruments/relays (b) Step up current for transmission (c) Convert AC to DC (d) Convert DC to AC
65. A Zener diode is commonly used for:
    (a) Voltage regulation, operating in reverse breakdown region (b) Only forward-bias rectification, identical to an ordinary diode (c) Only light emission (d) Only current amplification, identical to a BJT
66. An operational amplifier (op-amp) is commonly used in:
    (a) Amplification, filtering, and signal-conditioning circuits (b) Only mechanical switching applications (c) Only power transmission line protection (d) Only cement testing
67. A "PID controller" (proportional-integral-derivative) is commonly used in:
    (a) Industrial process/feedback control systems (b) Only decorative lighting circuits (c) Only battery charging with no feedback role (d) Only structural analysis software
68. The "proportional" term in a PID controller responds to:
    (a) The current error between desired and actual output (b) Only the error's rate of change (c) Only the accumulated error over time (d) No error at all
69. The "integral" term in a PID controller primarily helps to:
    (a) Eliminate steady-state error by accounting for accumulated past error (b) Increase steady-state error deliberately (c) Ignore all past error entirely (d) Replace the need for any proportional term
70. The "derivative" term in a PID controller primarily responds to:
    (a) The rate of change of error, improving response to rapid changes (b) Only the accumulated error over time (c) Only a fixed constant with no error dependence (d) Only the system's physical weight
71. A "transfer function" in control systems represents the relationship between:
    (a) System output and input in the frequency/Laplace domain (b) Only the system's physical dimensions (c) Only the system's colour (d) Only the system's cost
72. Stability of a linear control system can be analysed using techniques such as:
    (a) Root locus and Bode plot methods (b) Only visual inspection with no analytical method (c) Only random guessing (d) Only physical destructive testing
73. A "sensor" in a control/measurement system primarily serves to:
    (a) Detect a physical quantity and convert it into a usable signal (b) Generate mechanical power directly (c) Serve only a decorative function (d) Replace the need for any actuator
74. An "actuator" in a control system primarily serves to:
    (a) Convert a control signal into physical action/motion (b) Only measure a physical quantity with no output action (c) Serve only a decorative function (d) Replace the need for any sensor
75. A digital multimeter (DMM), compared to an analog multimeter, generally offers:
    (a) Higher accuracy and easier direct numeric reading (b) Lower accuracy with no other benefit (c) No practical difference whatsoever (d) Use exclusively for AC measurement, never DC
76. A tachometer is used to measure:
    (a) Rotational speed (b) Voltage only (c) Resistance only (d) Capacitance only
77. A frequency meter is used to measure:
    (a) The frequency of an AC supply/signal (b) Only DC voltage (c) Only mechanical vibration amplitude (d) Only resistance
78. In power electronics, "PWM" (Pulse Width Modulation) is commonly used to:
    (a) Control the effective average voltage/power delivered to a load by varying pulse width (b) Only measure voltage with no control function (c) Only generate audio signals with no power application (d) Only measure temperature
79. A "snubber circuit" in power electronic converters is used to:
    (a) Protect semiconductor devices from voltage/current transients during switching (b) Increase switching losses deliberately (c) Serve only a decorative function (d) Replace the need for any semiconductor device
80. Overall, measurement, electronics, and control topics are tested in RRB JE Electrical CBT 2 because:
    (a) These are foundational skills for electrical engineering practice, including instrumentation and automation (b) They have no relevance to electrical engineering practice (c) Only computer science students study these topics (d) These topics are tested only at postgraduate level

Section E: General Awareness, Computer Applications, and Current Affairs (20 Questions)

81. The Central Electricity Authority (CEA) in India is primarily responsible for:
    (a) Technical/policy matters relating to the power sector at the national level (b) Only railway ticketing (c) Only banking regulation (d) Only space research
82. The Central Electricity Regulatory Commission (CERC) primarily regulates:
    (a) Inter-state electricity tariffs and related matters at the central level (b) Only railway fares (c) Only banking interest rates (d) Only telecom tariffs
83. State Electricity Regulatory Commissions (SERCs) primarily regulate:
    (a) Intra-state electricity tariffs and related matters (b) Only inter-state railway matters (c) Only banking matters within a state (d) Only telecom matters within a state
84. Which government scheme focuses on providing round-the-clock quality power supply to rural and urban households in India?
    (a) Saubhagya (Pradhan Mantri Sahaj Bijli Har Ghar Yojana) (b) Only Ayushman Bharat, with no relation to electricity (c) Only Digital India, with no relation to electricity (d) Only Skill India, with no relation to electricity
85. Which of the following best describes India's push toward smart grid technology?
    (a) Using digital communication/automation to improve grid monitoring, control, and efficiency (b) A method of concrete curing (c) A method of soil compaction (d) A method of cement grading
86. Which Indian body is primarily responsible for standard-setting and quality certification (ISI mark) relevant to electrical appliances/equipment?
    (a) Bureau of Indian Standards (BIS) (b) Reserve Bank of India (c) Election Commission of India (d) Central Board of Secondary Education
87. In computer terminology, ROM stands for:
    (a) Read Only Memory (b) Random Output Module (c) Rapid Operating Memory (d) Remote Output Memory
88. A "compiler" in computing is a program that:
    (a) Translates source code into machine code (b) Prints documents (c) Scans images (d) Is a type of computer virus
89. Which of the following is an example of an operating system?
    (a) Windows (b) MS Excel (c) MS PowerPoint (d) Adobe Photoshop
90. In spreadsheet applications, the SUM function is used to:
    (a) Add up a range of numeric values (b) Delete a range of cells (c) Format cell borders only (d) Insert an image
91. Which of the following best describes India's push toward electric vehicle (EV) adoption?
    (a) Schemes such as FAME supporting faster EV adoption/manufacturing (b) Only traditional fuel subsidy schemes with no EV component (c) Only railway electrification schemes with no road-vehicle component (d) No such scheme exists in India
92. Which of the following best describes "net metering" for rooftop solar installations?
    (a) A billing mechanism crediting consumers for excess solar power fed back to the grid (b) A method of concrete curing (c) A method of soil compaction (d) A method of cement grading
93. Which of the following best describes India's renewable energy capacity targets in recent international commitments?
    (a) Increasing the share of energy from sources like solar and wind (b) Increasing reliance solely on coal-based power (c) Eliminating all forms of energy generation (d) Focusing solely on nuclear power with no other renewable source
94. Which Indian organisation is primarily responsible for space research and satellite launches?
    (a) Indian Space Research Organisation (ISRO) (b) Bureau of Indian Standards (c) Reserve Bank of India (d) Election Commission of India
95. Which of the following best describes India's "UPI" (Unified Payments Interface)?
    (a) A real-time digital payment system enabling instant bank-to-bank transfers (b) A type of railway ticket booking system exclusively (c) A type of electrical equipment testing standard (d) A type of surveying instrument
96. Which of the following best describes "Digital India Land Records Modernization Programme"?
    (a) Digitisation of land records for transparency and easier access (b) A railway ticket booking system (c) A banking loan disbursement system (d) An electrical equipment grading system
97. Which of the following best describes "Kavach," a system developed for Indian Railways?
    (a) An automatic train collision protection system (b) A type of railway ticket booking app (c) A type of railway station architecture (d) A type of railway track ballast material
98. Which of the following best describes the general objective of railway electrification programmes undertaken by Indian Railways?
    (a) Improving efficiency, reducing costs, and lowering emissions compared to diesel traction (b) Increasing diesel fuel consumption deliberately (c) Reducing train speed deliberately (d) Having no operational or environmental benefit
99. Which of the following best describes why RRB JE Electrical candidates should stay updated on power-sector current affairs alongside core technical topics?
    (a) The General Awareness section commonly draws on such current developments (b) Current affairs are never tested in RRB JE exams (c) Only technical topics are ever tested, with no current affairs component (d) Current affairs replace the need for technical preparation entirely
100. As an overall exam-readiness takeaway, RRB JE Electrical candidates should combine strong technical fundamentals with:
     (a) Regular practice, formula revision, and awareness of current developments (b) Reliance solely on rote memorisation with no conceptual understanding (c) Ignoring all technical fundamentals entirely (d) Avoiding any mock test practice

Answer Key with Explanations

1.(a) Ohm's Law holds at constant temperature/conditions.

2.(a) Resistance is measured in ohms.

3.(a) Capacitance is measured in farads.

4.(a) Inductance is measured in henries.

5.(a) DC power is P = VI.

6.(a) In a pure resistor, V and I are in phase.

7.(a) In a pure inductor, current lags voltage by 90 degrees.

8.(a) In a pure capacitor, current leads voltage by 90 degrees.

9.(a) Inductive reactance is 2πfL.

10.(a) Capacitive reactance is 1/(2πfC).

11.(a) Series RLC resonance occurs when XL equals XC.

12.(a) At resonance, impedance is minimum, equal to R.

13.(a) Impedance is the vector combination of resistance and reactance.

14.(a) Active power is measured in watts.

15.(a) Reactive power is measured in VAR.

16.(a) Apparent power is measured in VA.

17.(a) S² = P² + Q².

18.(a) Star connection: VL = √3 × Vph.

19.(a) Delta connection: IL = √3 × Iph.

20.(a) Three-phase power is √3 × VL × IL × cos φ.

21.(a) DC EMF equation involves conductors/poles/parallel paths along with flux/speed.

22.(a) A compound motor combines series and shunt field windings.

23.(a) The commutator converts AC (in armature) to DC output, or vice versa.

24.(a) Starting torque is generally lower than breakdown torque.

25.(a) Squirrel cage rotors use short-circuited bars with no external connection.

26.(a) Slip-ring rotors allow external resistance addition via slip rings.

27.(a) Adding rotor resistance improves wound-rotor starting torque.

28.(a) Auto-transformer starters reduce starting current via reduced start voltage.

29.(a) Star-delta starters start in star, then switch to delta.

30.(a) Ns = 120×50/4 = 1500 rpm.

31.(a) Voltage regulation relates no-load to full-load terminal voltage.

32.(a) Synchronising requires matching voltage, frequency, and phase sequence.

33.(a) Stepper motors rotate in discrete steps per input pulses.

34.(a) Servo motors provide precise position/speed control with feedback.

35.(a) Single-phase induction motors are not self-starting without auxiliary means.

36.(a) A capacitor-start motor creates a phase difference for starting torque.

37.(a) A universal motor runs on both AC and DC.

38.(a) Universal motors suit household mixers/vacuum cleaners for high speed/compact size.

39.(a) The no-load test determines core/iron losses.

40.(a) The short-circuit test determines copper losses/equivalent impedance.

41.(a) A generator transformer steps up voltage for efficient transmission.

42.(a) A substation performs voltage transformation and switching/protection.

43.(a) Corona loss becomes more significant at higher transmission voltages.

44.(a) A string insulator supports/insulates the conductor from the tower.

45.(a) Sag is the vertical difference between support level and conductor's lowest point.

46.(a) Skin effect concentrates current near the surface at higher frequencies.

47.(a) Ring main systems improve reliability via alternate-direction supply during a fault.

48.(a) Load factor is average load over maximum (peak) load.

49.(a) High load factor indicates uniform loading/better capacity utilisation.

50.(a) Demand factor is maximum demand over total connected load.

51.(a) A grid is an interconnected network of stations and transmission lines.

52.(a) Grid interconnection allows surplus power sharing/improved reliability.

53.(a) Lightning strikes and insulator failure commonly cause line faults.

54.(a) Single-line-to-ground faults are the most common transmission fault type.

55.(a) Three-phase faults are generally the most severe in fault current magnitude.

56.(a) Shunt capacitor banks improve voltage profile and reduce losses.

57.(a) A tap-changer adjusts turns ratio to regulate output voltage.

58.(a) An OLTC allows tap changes while the transformer remains energised/loaded.

59.(a) Power system stability is maintaining synchronism after a disturbance.

60.(a) Indian power systems show increasing renewable (solar/wind) integration.

61.(a) A Wheatstone bridge measures unknown resistance accurately.

62.(a) A CRO visually displays/measures waveforms.

63.(a) A CT steps down high current to a measurable low value.

64.(a) A PT steps down high voltage to a measurable low value.

65.(a) A Zener diode regulates voltage in reverse breakdown.

66.(a) Op-amps are used in amplification/filtering/signal-conditioning.

67.(a) PID controllers are used in industrial process/feedback control.

68.(a) The proportional term responds to current error.

69.(a) The integral term eliminates steady-state error via accumulated past error.

70.(a) The derivative term responds to the rate of change of error.

71.(a) A transfer function relates output to input in frequency/Laplace domain.

72.(a) Root locus and Bode plot methods analyse control system stability.

73.(a) A sensor detects a physical quantity and converts it to a usable signal.

74.(a) An actuator converts a control signal into physical action.

75.(a) Digital multimeters offer higher accuracy and easy numeric reading.

76.(a) A tachometer measures rotational speed.

77.(a) A frequency meter measures AC supply/signal frequency.

78.(a) PWM controls average voltage/power by varying pulse width.

79.(a) A snubber circuit protects devices from switching transients.

80.(a) These topics underpin electrical instrumentation/automation practice.

81.(a) CEA handles national-level power sector technical/policy matters.

82.(a) CERC regulates inter-state electricity tariffs.

83.(a) SERCs regulate intra-state electricity tariffs.

84.(a) Saubhagya targets round-the-clock household electrification.

85.(a) Smart grids use digital communication/automation for grid efficiency.

86.(a) BIS handles standard-setting/ISI certification.

87.(a) ROM stands for Read Only Memory.

88.(a) A compiler translates source code into machine code.

89.(a) Windows is an example operating system.

90.(a) SUM adds up a range of numeric values.

91.(a) FAME supports faster EV adoption/manufacturing.

92.(a) Net metering credits consumers for excess solar power fed to the grid.

93.(a) India targets increased solar/wind energy share.

94.(a) ISRO handles space research/satellite launches.

95.(a) UPI enables real-time bank-to-bank digital payments.

96.(a) The programme digitises land records for transparency/access.

97.(a) Kavach is an automatic train collision protection system.

98.(a) Electrification improves efficiency/cost/emissions versus diesel.

99.(a) Current developments are commonly tested in General Awareness.

100.(a) Exam readiness combines practice, revision, and current-affairs awareness.