Full-Length Mock Test 2 — RRB JE CBT 2 Technical Abilities Pattern (100 MCQs)
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Section A: Circuit Fundamentals and AC/DC Basics (20 Questions)
- The temperature coefficient of resistance for most pure metals is:
(a) Positive, i.e., resistance increases with temperature (b) Negative, i.e., resistance always decreases with temperature (c) Exactly zero for all metals (d) Undefined for metals - Semiconductors generally have a temperature coefficient of resistance that is:
(a) Negative, i.e., resistance decreases with increasing temperature (b) Always positive, identical to metals (c) Exactly zero always (d) Unrelated to temperature in any way - The "superposition theorem" cannot be directly applied to calculate:
(a) Power dissipated in a component in a multi-source linear circuit (directly via superposition of power) (b) Voltage across a component in a multi-source linear circuit (c) Current through a component in a multi-source linear circuit (d) Any quantity whatsoever in a linear circuit - A capacitor's energy storage is given by:
(a) (1/2)CV² (b) CV (c) C/V (d) V/C - An inductor's energy storage is given by:
(a) (1/2)LI² (b) LI (c) L/I (d) I/L - Capacitors in series combine similarly to how resistors combine in:
(a) Parallel (reciprocal sum) (b) Series (direct sum) (c) Neither pattern applies to capacitors (d) A pattern identical to inductors in parallel only - Capacitors in parallel combine similarly to how resistors combine in:
(a) Series (direct sum) (b) Parallel (reciprocal sum) (c) Neither pattern applies (d) A pattern identical to inductors in series only - In a purely inductive AC circuit, average power consumed over a complete cycle is:
(a) Zero (b) Maximum, equal to VI (c) Equal to VI/2 always (d) Undefined - In a purely capacitive AC circuit, average power consumed over a complete cycle is:
(a) Zero (b) Maximum, equal to VI (c) Equal to VI/2 always (d) Undefined - The time constant of an RC circuit is given by:
(a) RC (b) R/C (c) R+C (d) 1/(RC) - The time constant of an RL circuit is given by:
(a) L/R (b) LR (c) R/L (d) 1/(LR) - After one time constant, a charging RC circuit's capacitor voltage reaches approximately what percentage of its final value?
(a) 63 percent (b) 100 percent (c) 0 percent (d) 50 percent - A "star-delta" transformation is used in circuit analysis to:
(a) Simplify complex resistor networks that are neither pure series nor pure parallel (b) Convert AC to DC directly (c) Measure capacitance directly (d) Measure inductance directly - Which of the following is a passive circuit element?
(a) Resistor (b) Operational amplifier (used as an active gain element) (c) Transistor (used as an active device) (d) Battery acting as an active source - Which of the following is generally considered an active circuit element?
(a) An independent voltage/current source (b) A resistor (c) A capacitor (d) An inductor - The "quality factor" (Q) of a series RLC circuit at resonance relates to:
(a) The sharpness of the resonance (bandwidth relative to resonant frequency) (b) Only the circuit's physical size (c) Only the circuit's colour (d) Only the circuit's cost - A higher Q factor in a resonant circuit generally indicates:
(a) A sharper, narrower resonance peak (b) A broader, less selective resonance (c) No relation to resonance sharpness (d) Complete absence of any resonance - "Power factor" close to unity is generally desirable in an AC system because it:
(a) Minimises reactive power/current draw for a given real power (b) Maximises reactive power draw deliberately (c) Has no bearing on current draw (d) Always indicates a fault condition - A "phasor" is used in AC circuit analysis to represent:
(a) A sinusoidal quantity's magnitude and phase as a rotating vector (b) Only a DC quantity with no phase information (c) Only mechanical rotation with no electrical meaning (d) Only the circuit's physical layout - The RMS value of a DC quantity, by definition, is:
(a) Equal to its constant (DC) value itself (b) Always zero (c) Always undefined (d) Always equal to the AC RMS formula regardless of waveform
Section B: Electrical Machines (20 Questions)
- A DC shunt generator, compared to a DC series generator, is more suitable for:
(a) Applications requiring relatively constant voltage regardless of load (b) Applications requiring voltage to rise sharply with load current (c) Applications with absolutely no load variation ever, only theoretical use (d) Traction applications exclusively - "Armature reaction" in a DC machine refers to:
(a) The effect of armature current's magnetic field distorting/weakening the main field (b) A purely mechanical vibration with no magnetic cause (c) The commutator's physical wear only (d) The brush material's chemical composition only - "Interpoles" (commutating poles) in a DC machine are provided primarily to:
(a) Improve commutation and reduce sparking at the brushes (b) Increase the machine's physical size with no functional benefit (c) Replace the need for a commutator entirely (d) Serve only a decorative function - A DC motor's back EMF opposes the applied voltage and is proportional to:
(a) Speed and flux (b) Only the machine's physical weight (c) Only the ambient temperature (d) Only the armature resistance - As a DC motor's speed increases (with constant flux), its back EMF:
(a) Increases (b) Decreases (c) Remains exactly constant regardless of speed (d) Becomes negative - A transformer's "all-day efficiency" is particularly relevant for transformers that:
(a) Operate under significantly varying load over a 24-hour period, such as distribution transformers (b) Never experience any load variation whatsoever (c) Operate only at exactly full load continuously with no variation (d) Are used only in laboratory testing with no field application - An "auto-transformer," compared to a conventional two-winding transformer, has:
(a) A single winding shared between primary and secondary, providing partial electrical connection (b) Two completely separate, electrically isolated windings with no shared turns at all (c) No winding at all (d) Only a DC application, never AC - A key limitation of an auto-transformer, compared to a conventional isolation transformer, is:
(a) Lack of electrical isolation between primary and secondary (b) Complete inability to transform voltage at all (c) Use exclusively at extra-low voltage with no other application (d) Requirement for a rotating armature - A three-phase transformer can be constructed as:
(a) A single three-phase unit, or a bank of three single-phase transformers (b) Only a bank of exactly two single-phase units (c) Only a single-phase unit with no three-phase configuration possible (d) Only usable at DC - Transformer "vector group" designation (e.g., Dyn11) indicates:
(a) The winding connections and phase displacement between primary and secondary (b) Only the transformer's physical weight (c) Only the transformer's manufacturer (d) Only the transformer's colour - A "double squirrel cage" induction motor rotor design is used primarily to:
(a) Improve starting torque while maintaining good running characteristics (b) Eliminate the need for any stator winding (c) Convert the motor to a synchronous machine (d) Serve only a decorative rotor design with no functional benefit - "Crawling" is a phenomenon sometimes observed in induction motors, related to:
(a) The motor locking into a lower stable speed due to harmonic effects, rather than reaching normal running speed (b) Complete inability to rotate at all under any condition (c) A beneficial design feature with no drawback (d) A phenomenon exclusive to DC machines, never AC induction motors - "Cogging" in an induction motor refers to:
(a) A tendency to refuse to start due to slot harmonics locking rotor and stator teeth magnetically (b) A beneficial smooth-starting characteristic (c) A phenomenon exclusive to transformers, never motors (d) A phenomenon exclusive to synchronous generators, never induction motors - A synchronous motor's power factor can be adjusted (leading, lagging, or unity) primarily by varying its:
(a) Field excitation current (b) Physical rotor size only (c) Stator winding colour only (d) Ambient temperature only - A synchronous condenser is essentially a synchronous machine operated primarily to:
(a) Provide reactive power compensation without significant mechanical load (b) Generate significant real power exclusively with no reactive function (c) Serve only as a mechanical flywheel with no electrical function (d) Convert AC to DC directly - "Hunting" in a synchronous machine refers to:
(a) Oscillation of the rotor about its steady-state synchronous position following a disturbance (b) A beneficial steady-state operating condition with no oscillation (c) A phenomenon exclusive to DC machines (d) A phenomenon exclusive to transformers - Damper windings in a synchronous machine primarily help to:
(a) Reduce hunting oscillations and assist starting (in synchronous motors) (b) Increase hunting oscillations deliberately (c) Replace the need for the main field winding (d) Serve only a decorative function - A "brushless DC motor" (BLDC), despite its name, is fundamentally driven by:
(a) Electronically commutated AC-like current, without mechanical brushes/commutator (b) A conventional mechanical commutator and brushes, identical to a standard DC motor (c) Only a manually operated switch with no electronic control (d) Only a purely mechanical, non-electrical drive mechanism - Which of the following is a key advantage of a BLDC motor over a conventional brushed DC motor?
(a) Reduced maintenance, since there are no brushes to wear out (b) Significantly higher required maintenance due to added brushes (c) Complete inability to control speed (d) Use exclusively in very low-power toy applications with no industrial relevance - A three-phase induction motor's direction of rotation can be reversed by:
(a) Interchanging any two of the three supply phase connections (b) Interchanging all three phase connections simultaneously with no net effect (c) Increasing the supply voltage only (d) Increasing the supply frequency only
Section C: Power Systems and Protection (20 Questions)
- The "economic loading" of a power plant/generating unit generally refers to operating it at a load level that:
(a) Minimises the overall cost of generation (b) Always maximises fuel consumption regardless of cost (c) Ignores cost considerations entirely (d) Is fixed at exactly zero load at all times - "Merit order dispatch" in power system operation refers to:
(a) Dispatching generating units in increasing order of their operating cost, to minimise overall system cost (b) Dispatching units in a completely random order with no cost consideration (c) Dispatching only the most expensive units first, deliberately (d) A concept applicable only to distribution systems, never generation - A power system's "spinning reserve" refers to:
(a) Generating capacity already synchronised and available to quickly increase output if needed (b) Reserve capacity that takes several days to bring online (c) A purely theoretical concept with no practical implementation (d) Capacity available only for scheduled maintenance outages - "Black start" capability of a generating unit refers to its ability to:
(a) Start up and begin supplying power without relying on the external grid (b) Operate only when the entire grid is already fully energised (c) Operate only during daylight hours (d) Operate only at exactly rated full load with no partial-load capability - A "feeder" in a distribution system refers to:
(a) A conductor/circuit carrying power from a substation to a load area or distribution transformer (b) Only a decorative pole structure with no electrical function (c) Only a protective relay (d) Only a billing meter - "Ferranti effect" on a long transmission line refers to:
(a) The receiving-end voltage exceeding the sending-end voltage under light-load/no-load conditions (b) The receiving-end voltage always being lower than sending-end voltage under all conditions (c) A phenomenon exclusive to DC lines, never AC (d) A phenomenon exclusive to underground cables, never overhead lines - Series compensation of a long transmission line using series capacitors is primarily used to:
(a) Reduce the line's effective reactance, improving power transfer capability (b) Increase the line's reactance deliberately (c) Convert the line to DC operation (d) Eliminate the need for any protection scheme - Shunt compensation of a transmission line using shunt reactors is primarily used to:
(a) Absorb excess reactive power/limit voltage rise, especially under light load (b) Increase voltage rise deliberately under all conditions (c) Convert the line to DC operation (d) Eliminate the need for any circuit breaker - HVDC transmission, compared to HVAC, generally avoids the issue of:
(a) Reactive power/charging current concerns over very long distances (b) Any form of power loss whatsoever (c) The need for any converter station (d) The need for any insulation at all - A "converter station" in an HVDC system performs:
(a) AC-to-DC conversion at the sending end and DC-to-AC conversion at the receiving end (b) Only voltage transformation with no AC/DC conversion (c) Only mechanical switching with no conversion function (d) Only billing/metering functions - Which of the following best describes the general function of a "static VAR compensator" (SVC) in a power system?
(a) Providing fast-acting reactive power compensation to support voltage (b) Providing only real power generation with no reactive function (c) Serving only as a decorative substation structure (d) Replacing the need for any transmission line entirely - A "power system stabiliser" (PSS) is used with generator excitation systems primarily to:
(a) Damp low-frequency power system oscillations (b) Increase oscillations deliberately (c) Replace the need for any voltage regulator (d) Serve only a cosmetic monitoring function with no control action - An "automatic voltage regulator" (AVR) on a generator primarily controls:
(a) The generator's field excitation to maintain desired terminal voltage (b) The generator's mechanical speed exclusively, with no voltage role (c) Only the generator's physical cooling system (d) Only the generator's paint colour - A "governor" on a generating unit's prime mover primarily controls:
(a) The mechanical speed/frequency of the generating unit (b) Only the generator's terminal voltage, with no speed role (c) Only the generator's physical weight (d) Only the generator's paint colour - Frequency in an interconnected power system is primarily controlled through:
(a) Balancing generation and load via governor action across generating units (b) Only voltage regulation with no relation to frequency (c) Only reactive power compensation with no relation to frequency (d) No active control; frequency is left entirely uncontrolled - A drop in system frequency below nominal generally indicates:
(a) Generation is insufficient relative to demand (b) Generation is always exactly matched to demand under all conditions (c) A purely cosmetic reading with no operational significance (d) An intentional, harmless daily variation with no cause - "Load shedding" during a generation shortfall is used to:
(a) Deliberately disconnect some load to maintain system stability/frequency (b) Increase generation instantly with no load-side action (c) Serve only a punitive purpose with no technical justification (d) Have no effect on system frequency whatsoever - Under-frequency relays are used to automatically:
(a) Initiate load shedding when frequency falls below a set threshold (b) Increase system frequency directly (c) Increase generation directly with no load-side action (d) Serve no protective function - A key objective of power system protection coordination between successive protective devices is to:
(a) Ensure the device closest to a fault operates first, minimising the outage extent (b) Ensure all devices trip simultaneously regardless of fault location (c) Prevent any device from ever operating (d) Serve only a documentation purpose with no operational relevance - Overall, understanding power system operation and protection concepts is essential for RRB JE Electrical candidates because:
(a) These concepts underlie the safe, reliable operation of real power systems they may work with (b) They have no relevance to electrical engineering practice (c) Only senior engineers, never JEs, need this understanding (d) This knowledge is tested only in interviews, never the written exam
Section D: Measurements, Electronics, Control, and Power Electronics (20 Questions)
- A "bridge rectifier" combined with a smoothing capacitor and voltage regulator IC is a common configuration for:
(a) A simple regulated DC power supply (b) A pure AC signal generator with no DC output (c) A frequency counter (d) A mechanical relay - A "voltage regulator IC" (e.g., a 7805-type device) is used to:
(a) Provide a stable, fixed output voltage regardless of moderate input variation (b) Convert DC to three-phase AC directly (c) Measure resistance directly (d) Measure capacitance directly - An "op-amp comparator" circuit is used to:
(a) Compare two input voltages and produce a corresponding high/low output (b) Only amplify audio signals with no comparison function (c) Only measure temperature directly (d) Only generate three-phase AC power - A "555 timer IC" is commonly used in:
(a) Timing, pulse generation, and oscillator circuits (b) Only high-voltage transmission line protection (c) Only concrete strength testing (d) Only soil classification testing - In digital electronics, a "logic gate" performs:
(a) A basic Boolean logic operation on binary inputs (b) Only analog signal amplification (c) Only mechanical switching with no logic function (d) Only power transmission - An "AND gate" produces a high output only when:
(a) All its inputs are high (b) Any single input is high, regardless of others (c) All inputs are low (d) Exactly one input is high and the rest are low - An "OR gate" produces a high output when:
(a) At least one input is high (b) All inputs must be high simultaneously with no exception (c) All inputs are low (d) Never, regardless of input state - A "NOT gate" (inverter) produces an output that is:
(a) The logical inverse of its single input (b) Identical to its input at all times (c) Always high regardless of input (d) Always low regardless of input - An "analog-to-digital converter" (ADC) is used to:
(a) Convert a continuous analog signal into a discrete digital representation (b) Convert digital data back into an analog signal exclusively (c) Only amplify analog signals with no conversion (d) Only generate three-phase power - A "digital-to-analog converter" (DAC) performs the reverse function of:
(a) An ADC (b) A simple resistor (c) A simple switch (d) A simple fuse - A "microcontroller" (e.g., used in embedded control applications) typically integrates:
(a) A processor, memory, and input/output peripherals on a single chip (b) Only a single resistor with no processing capability (c) Only a mechanical relay with no digital logic (d) Only a power transformer - PLCs (Programmable Logic Controllers) are widely used in:
(a) Industrial automation and process control (b) Only household lighting switches (c) Only decorative displays (d) Only manual, non-automated processes - A PLC's typical inputs might include sensors, while its outputs commonly drive:
(a) Actuators such as motors, valves, and contactors (b) Only decorative indicator lamps with no other function (c) No physical devices at all (d) Only internal software variables with no real-world effect - A "SCADA" (Supervisory Control and Data Acquisition) system is used to:
(a) Remotely monitor and control geographically distributed industrial/utility processes (b) Only provide local, single-site manual control with no remote capability (c) Only measure ambient temperature at a single point (d) Only manage payroll data - In power systems, SCADA is commonly used for:
(a) Remote monitoring/control of substations and grid operations (b) Only billing of household consumers (c) Only architectural design of substations (d) Only structural analysis of transmission towers - A "harmonic" in an electrical waveform refers to a component at a frequency that is:
(a) An integer multiple of the fundamental frequency (b) Always exactly equal to the fundamental frequency (c) Always lower than the fundamental frequency (d) Unrelated to the fundamental frequency in any way - Harmonics in a power system are commonly caused by:
(a) Non-linear loads such as variable frequency drives and rectifiers (b) Only purely linear resistive loads (c) Only ideal, lossless transmission lines (d) No practical source; harmonics never occur in real systems - Excessive harmonic distortion in a power system can lead to:
(a) Increased losses and potential equipment overheating/malfunction (b) Improved efficiency with no drawback (c) No practical consequence whatsoever (d) Automatic correction with no mitigation needed - Harmonic filters are used in power systems to:
(a) Reduce harmonic distortion levels (b) Increase harmonic distortion deliberately (c) Serve only a decorative function (d) Replace the need for any protective relay - Overall, digital electronics, PLCs, and SCADA topics reflect the reality that modern electrical engineering practice increasingly involves:
(a) Automation and digital control alongside traditional power/machines knowledge (b) Only traditional, non-digital methods with no automation relevance (c) Only mechanical engineering concepts with no electrical relevance (d) No relevance to RRB JE Electrical preparation at all
Section E: General Awareness, Computer Applications, and Current Affairs (20 Questions)
- Which of the following best describes India's National Smart Grid Mission?
(a) A mission to accelerate smart grid deployment for improved grid efficiency/reliability (b) A mission focused solely on space research (c) A mission focused solely on banking reform (d) A mission focused solely on railway ticketing - Which of the following best describes India's UDAY (Ujwal DISCOM Assurance Yojana) scheme?
(a) A scheme aimed at financial/operational turnaround of power distribution companies (b) A railway modernisation scheme (c) A banking sector reform scheme (d) A space research scheme - Which of the following best describes "one nation, one grid" as it applies to India's power sector?
(a) A unified national power grid enabling power transfer/sharing across regions (b) A programme focused solely on railway ticketing (c) A programme focused solely on space research (d) A programme focused solely on banking regulation - Which of the following best describes India's push toward rooftop solar installations under various government schemes?
(a) Encouraging distributed solar generation to supplement grid supply and reduce bills (b) A programme unrelated to electricity generation (c) A programme focused solely on railway electrification (d) A programme focused solely on banking reform - Which of the following best describes the "Central Electricity Authority's" role in India's power sector planning?
(a) Technical and policy-planning matters for the power sector at the national level (b) Only railway ticketing (c) Only banking regulation (d) Only space research - In computing, "RAM" stands for:
(a) Random Access Memory (b) Read Access Module (c) Rapid Application Mode (d) Remote Access Memory - A "firewall" in computer networking is primarily used to:
(a) Monitor/control network traffic for security (b) Increase internet speed only (c) Store large files only (d) Print documents - Which of the following best describes "cloud computing"?
(a) On-demand delivery of computing resources/storage over the internet (b) A method of concrete curing (c) A method of soil stabilisation (d) A method of surveying - Which of the following best describes "cybersecurity"?
(a) Protection of computer systems/networks from digital attacks/unauthorised access (b) Only physical building security (c) Only fire safety measures (d) Only structural safety of a bridge - Which of the following best describes "e-governance" initiatives relevant to utility service delivery in India?
(a) Delivering government/utility services to citizens using digital technology (b) Eliminating all government services entirely (c) Replacing elections with digital voting exclusively (d) Serving only internal government email needs - Which of the following best describes India's "Production Linked Incentive" (PLI) scheme, including for electronics/renewable equipment manufacturing?
(a) A scheme providing financial incentives to boost domestic manufacturing output (b) A scheme providing free railway travel (c) A scheme providing free housing (d) A scheme providing free higher education - Which of the following best describes "Make in India," relevant to domestic electrical equipment manufacturing?
(a) A programme encouraging domestic/foreign investment in manufacturing (b) A programme focused solely on foreign travel promotion (c) A programme with no economic component (d) A programme focused solely on agriculture exports - Which of the following best describes India's overall approach to expanding railway electrification?
(a) Continued expansion of electrified rail routes for efficiency/emissions benefits (b) A complete freeze on further electrification (c) Exclusive focus on international projects with no domestic development (d) A focus solely on ticket pricing with no infrastructure development - Which of the following best describes the "National Career Service" (NCS) portal's relevance to technical job seekers?
(a) It provides a platform to search for jobs, including technical/engineering positions (b) It provides free housing exclusively (c) It provides free railway travel exclusively (d) It has no relevance to job seekers - Which of the following best describes "artificial intelligence" (AI) applications increasingly relevant to power system operation?
(a) Predictive maintenance and grid optimisation (b) Only decorative interior design suggestions (c) No practical application at all (d) Only entertainment/gaming applications - Which of the following best describes "IoT" (Internet of Things) as applied to smart electrical meters/appliances?
(a) Interconnected physical devices that collect and exchange data over a network (b) A single standalone computer with no networking (c) A type of concrete admixture (d) A type of surveying instrument - Which of the following best describes the relevance of the RRB JE technical syllabus to a Junior Engineer's expected duties?
(a) JEs are expected to apply sound technical fundamentals in real railway electrical infrastructure work (b) The syllabus has no relevance to actual job duties (c) Only general awareness matters for the role (d) Only computer applications matter for the role - Which of the following best describes the value of solving full-length mock tests during RRB JE exam preparation?
(a) Building exam-pattern familiarity, time management, and identifying weak areas (b) No value at all compared to reading theory alone (c) Only useful for the General Awareness section (d) Only useful in the final week before the exam - Which of the following best describes a balanced RRB JE Electrical Engineering preparation strategy?
(a) Combining conceptual understanding, practice questions, and revision of formulas/current affairs (b) Relying solely on memorising past question papers with no conceptual study (c) Relying solely on general awareness with no technical study (d) Ignoring all revision and relying only on a single read-through - Ultimately, consistent and structured preparation across all technical and general sections is valuable because:
(a) The RRB JE CBT 2 exam tests a broad, integrated range of subject areas (b) Only one section is ever scored in the final result (c) Sections are scored independently with no combined relevance (d) The exam pattern changes completely and unpredictably every single year
Answer Key with Explanations
1.(a) Pure metals generally have a positive temperature coefficient of resistance.
2.(a) Semiconductors generally have a negative temperature coefficient.
3.(a) Superposition cannot be directly applied to power since power is a squared (non-linear) quantity.
4.(a) Capacitor energy is (1/2)CV².
5.(a) Inductor energy is (1/2)LI².
6.(a) Series capacitors combine like parallel resistors (reciprocal sum).
7.(a) Parallel capacitors combine like series resistors (direct sum).
8.(a) Average power in a pure inductor over a cycle is zero.
9.(a) Average power in a pure capacitor over a cycle is zero.
10.(a) RC time constant is RC.
11.(a) RL time constant is L/R.
12.(a) After one time constant, capacitor voltage reaches about 63 percent of final value.
13.(a) Star-delta transformation simplifies non-series/non-parallel resistor networks.
14.(a) A resistor is a passive element.
15.(a) An independent source is an active element.
16.(a) Q factor relates to resonance sharpness/bandwidth.
17.(a) Higher Q gives a sharper resonance peak.
18.(a) Unity power factor minimises reactive power/current draw.
19.(a) A phasor represents a sinusoid's magnitude/phase as a rotating vector.
20.(a) A DC quantity's RMS value equals its constant value.
21.(a) Shunt generators suit relatively constant-voltage applications.
22.(a) Armature reaction is armature current's field distorting/weakening the main field.
23.(a) Interpoles improve commutation, reducing brush sparking.
24.(a) Back EMF is proportional to speed and flux.
25.(a) Back EMF increases with speed at constant flux.
26.(a) All-day efficiency matters for varying-load transformers like distribution units.
27.(a) An auto-transformer shares a single winding between primary/secondary.
28.(a) Auto-transformers lack electrical isolation, unlike two-winding transformers.
29.(a) Three-phase transformers can be one unit or a bank of three single-phase units.
30.(a) Vector group indicates winding connections and phase displacement.
31.(a) Double squirrel cage rotors improve starting torque while keeping good running behaviour.
32.(a) Crawling is locking into a lower stable speed from harmonic effects.
33.(a) Cogging is a starting refusal from slot-harmonic tooth locking.
34.(a) Synchronous motor power factor is adjusted via field excitation.
35.(a) A synchronous condenser mainly provides reactive power compensation.
36.(a) Hunting is rotor oscillation about steady-state position after a disturbance.
37.(a) Damper windings reduce hunting and assist starting.
38.(a) BLDC motors use electronically commutated current without brushes.
39.(a) BLDC motors need less maintenance since there are no brushes.
40.(a) Reversing rotation needs interchanging any two of three phase connections.
41.(a) Economic loading minimises overall generation cost.
42.(a) Merit order dispatch orders units by increasing operating cost.
43.(a) Spinning reserve is synchronised capacity ready to quickly increase output.
44.(a) Black start capability starts a unit without relying on the external grid.
45.(a) A feeder carries power from a substation to a load area/transformer.
46.(a) Ferranti effect raises receiving-end voltage above sending-end under light load.
47.(a) Series capacitors reduce effective line reactance, improving transfer capability.
48.(a) Shunt reactors absorb excess reactive power/limit voltage rise under light load.
49.(a) HVDC avoids reactive power/charging current issues over very long distances.
50.(a) A converter station does AC-DC conversion at sending end, DC-AC at receiving end.
51.(a) An SVC provides fast-acting reactive power compensation for voltage support.
52.(a) A PSS damps low-frequency power system oscillations.
53.(a) An AVR controls field excitation to maintain terminal voltage.
54.(a) A governor controls the prime mover's mechanical speed/frequency.
55.(a) Frequency control balances generation and load via governor action.
56.(a) Falling frequency indicates generation is insufficient relative to demand.
57.(a) Load shedding disconnects load deliberately to maintain stability/frequency.
58.(a) Under-frequency relays initiate load shedding below a set threshold.
59.(a) Protection coordination ensures the nearest device trips first, minimising outage extent.
60.(a) Power system operation/protection knowledge underlies safe, reliable real system operation.
61.(a) Bridge rectifier + capacitor + regulator IC is a common regulated DC supply.
62.(a) A regulator IC provides a stable fixed output voltage.
63.(a) An op-amp comparator compares two voltages, giving a high/low output.
64.(a) A 555 timer IC is used in timing/pulse/oscillator circuits.
65.(a) A logic gate performs a Boolean operation on binary inputs.
66.(a) An AND gate outputs high only when all inputs are high.
67.(a) An OR gate outputs high when at least one input is high.
68.(a) A NOT gate inverts its single input.
69.(a) An ADC converts analog signals to digital representation.
70.(a) A DAC reverses an ADC's function.
71.(a) A microcontroller integrates processor, memory, and I/O on one chip.
72.(a) PLCs are widely used in industrial automation/process control.
73.(a) PLC outputs commonly drive actuators like motors/valves/contactors.
74.(a) SCADA remotely monitors/controls distributed industrial/utility processes.
75.(a) SCADA is used for remote substation/grid monitoring and control.
76.(a) A harmonic is an integer multiple of the fundamental frequency.
77.(a) Non-linear loads like VFDs/rectifiers commonly cause harmonics.
78.(a) Excessive harmonics increase losses and can cause equipment issues.
79.(a) Harmonic filters reduce distortion levels.
80.(a) Automation/digital control increasingly complement traditional power/machines knowledge.
81.(a) The National Smart Grid Mission accelerates smart grid deployment.
82.(a) UDAY targets DISCOM financial/operational turnaround.
83.(a) One nation, one grid means a unified national grid for power sharing.
84.(a) Rooftop solar schemes encourage distributed generation to cut bills.
85.(a) CEA handles national power-sector technical/policy planning.
86.(a) RAM stands for Random Access Memory.
87.(a) A firewall monitors/controls network traffic for security.
88.(a) Cloud computing delivers computing resources on demand over the internet.
89.(a) Cybersecurity protects systems/networks from digital attacks.
90.(a) E-governance delivers services digitally to citizens.
91.(a) PLI provides incentives to boost domestic manufacturing.
92.(a) Make in India encourages manufacturing investment.
93.(a) India continues expanding rail electrification for efficiency/emissions benefits.
94.(a) NCS provides a job-search platform including technical roles.
95.(a) AI supports predictive maintenance/grid optimisation.
96.(a) IoT is interconnected devices exchanging data over a network.
97.(a) The syllabus reflects real technical duties expected of JEs.
98.(a) Mock tests build familiarity, time management, and reveal weak areas.
99.(a) A balanced strategy combines concepts, practice, and revision.
100.(a) The CBT 2 exam integrates broad technical and general subject areas.