Assistant Engineer (Electrical), Class-2, Road and Building Department – Verified PYQ Authority Guide
Assistant Engineer (Electrical), Class-2, Road and Building Department is an exam authority hub based on SRO’s verified mapped PYQs. It helps students see the papers/years and technical areas represented in the current corpus and move directly into solved exam questions. Every factual learning cue below is drawn from the existing verified, published and approved English PYQ corpus or from its Knowledge Graph relationships; the hub does not invent unsupported technical claims.
PYQ evidence snapshot
180 verified PYQs are currently mapped to this Exam hub. The represented years include 2025. Exam coverage currently includes Assistant Engineer (Electrical), Class-2, Road and Building Department. Subject context includes Electrical Engineering. These values come from live mappings and can expand automatically when new verified PYQs are added.
Most useful verified PYQs to solve first
Start with the actual questions rather than memorising a generic note. The links below are ranked from the mapped corpus using repeat history and editorial quality, while the complete explanation stays on the individual question page.
- For a balanced three phase, three wire system with input power of 10 kW at 0.9 power factor, the readings on both wattmeter are _________ respectively
Assistant Engineer (Electrical), Class-2, Road and Building Department · 2025 · Wattmeter Readings from Total Power and Power Factor
For a balanced three-phase load, W₁+W₂=P=10 kW and tanφ=√3(W₁−W₂)/(W₁+W₂). With cosφ=0.9, φ≈25.84°; solving gives W₁≈6.40 kW and W₂≈3.60 kW, nearest to 6350 W and… - What is the primary function of an RCCB (Residual Current Circuit Breaker) in an electrical system?
Assistant Engineer (Electrical), Class-2, Road and Building Department · 2025 · RCCB
An RCCB protects people against dangerous earth-leakage/residual current by comparing the currents in live and neutral conductors. If the imbalance exceeds its trip threshold,… - According to IS 3043, the resistance of an earth connection for a large power station should be as low as possible, ideally not exceeding __________.
Assistant Engineer (Electrical), Class-2, Road and Building Department · 2025 · Power Station Earth Resistance
For a large power station, earth resistance should be extremely low so high fault currents can return safely and protective devices operate quickly. The… - __________ is the normal length of the cable sample used for testing.
Assistant Engineer (Electrical), Class-2, Road and Building Department · 2025 · Cable Sample Length for Tests
For laboratory/factory tests that require a representative cable section while remaining practical to handle, a normal sample length is in the range of about… - How the sag at higher stages can be reduced in a voltage multiplier circuit?
Assistant Engineer (Electrical), Class-2, Road and Building Department · 2025 · Voltage Multiplier Sag Reduction
In a Cockcroft-Walton multiplier, voltage sag/ripple becomes more severe toward the higher-output stages because charging currents pass through preceding capacitors. Increasing capacitance in the… - HVDC LCCs have ______________
Assistant Engineer (Electrical), Class-2, Road and Building Department · 2025 · Degrees of Freedom in LCC HVDC
A line-commutated converter is fundamentally controlled through its firing angle, giving one principal control degree of freedom per converter bridge for steady-state DC voltage/current… - The number of idle states (Ti), that is allowed between two INTA cycles, to meet the 8259A speed and cascade address output delay is
Assistant Engineer (Electrical), Class-2, Road and Building Department · 2025 · Idle States Between INTA Cycles
The 8259A interrupt-acknowledge sequence may require idle timing between INTA̅ cycles to satisfy PIC speed and cascade-address delays. Under the specified interface convention, three… - A valid HOLD request is ascertained only after the completion of
Assistant Engineer (Electrical), Class-2, Road and Building Department · 2025 · HOLD Request Recognition
Under the 80286 bus-timing convention used by the question, a valid HOLD request is recognized only after completion of the specified bus-cycle sequence with…
Formula & key-relationship bank from verified solutions
P = W₁ + W₂ = 10,000 W φ = cos⁻¹(0.9) tanφ ≈ 0.4843 tanφ = √3(W₁−W₂)/(W₁+W₂) W₁−W₂ = P tanφ/√3 ≈ 10,000×0.4843/1.732 ≈ 2796 W W₁ ≈ (10,000+2796)/2 ≈…I_Δ = |I_L − I_N| If I_Δ ≥ trip threshold → RCCB tripsEarth-potential rise: EPR ≈ I_fault × R_grid Lower R_grid → lower EPR for the same ground-fault currentTypical laboratory cable specimen: order of metres, not hundreds of metres.For multiplier ladders, load-dependent ripple/sag is approximately proportional to: I/(fC) Larger C ⇒ smaller ripple/sagIdeal 6-pulse bridge: V_d = V_d0 cosα − commutation drop Main controllable variable: α
Use these as revision triggers and open the linked PYQ before applying a formula numerically; variable definitions and assumptions belong to the exact solved question.
Core ideas repeatedly reinforced by the solved corpus
- For a balanced three-phase load, W₁+W₂=P=10 kW and tanφ=√3(W₁−W₂)/(W₁+W₂). With cosφ=0.9, φ≈25.84°; solving gives W₁≈6.40 kW and W₂≈3.60 kW, nearest to 6350 W and 3650 W.
- An RCCB protects people against dangerous earth-leakage/residual current by comparing the currents in live and neutral conductors. If the imbalance exceeds its trip threshold, it disconnects the circuit rapidly.
- For a large power station, earth resistance should be extremely low so high fault currents can return safely and protective devices operate quickly. The exam's IS 3043-based target is ideally not exceeding about 0.5 Ω.
- For laboratory/factory tests that require a representative cable section while remaining practical to handle, a normal sample length is in the range of about 50 cm to 10 m, matching the keyed option.
- In a Cockcroft-Walton multiplier, voltage sag/ripple becomes more severe toward the higher-output stages because charging currents pass through preceding capacitors. Increasing capacitance in the higher stages is one effective grading measure to reduce the voltage sag there, which…
Exam tips already validated in SRO solutions
- Check that W₁+W₂ is approximately 10 kW for any candidate.
- Remember RCCB ≠ MCB. MCB protects overcurrent; RCCB detects imbalance.
- Resistance is one criterion; safe touch/step voltage is the deeper design objective.
- Do not generalize this broad range to every IEC/IS test; specific standards can prescribe exact dimensions.
- Use the official final key rather than the provisional highlight for revised questions.
Common mistakes to avoid
- Choosing 5 kW,5 kW; equal readings imply unity power factor, not 0.9.
- Selecting short-circuit protection as the primary RCCB function.
- Applying a domestic installation earth-resistance rule to a large station grid.
- Choosing above 100 m as though a factory sample were an installed feeder length.
- Decreasing capacitance when trying to reduce sag.
Topic and concept coverage
Mapped topic labels include Renewable Energy Policy, Electricity Legislation, Sequential Logic, Indian Standards, Steam Power Plants, High Voltage Engineering, Transformers. The concept trail includes Air-Gap Line, Annual Average Load, Anode-Short GTO Two-Transistor Model, Aperiodic Signal Definition, APTEL under Electricity Act 2003, Autocorrelation of Rectangular Pulse, Average Power in an Inductor, BCD-to-Decimal Decoder Inputs. Use these labels as a revision map: move from the broad area to the narrow concept, solve a verified PYQ, inspect the detailed reasoning, and then attempt another question from the same cluster.
Knowledge Graph navigation
Continue with Gujarat Public Service Commission (GPSC), Preliminary Test, Preliminary Test, Preliminary Test, Preliminary Test, Preliminary Test, Electrical Engineering, Electrical Laws, Standards and Energy Policy, Electrical Machines, Power System, Building Electrical Services, Signals and Systems. These are canonical SRO entity links based on the Knowledge Graph and shared question mappings, not keyword-stuffed tag pages.
How to revise this authority page efficiently
- Solve before reading: answer a mapped PYQ first.
- Read the exact explanation: verify the correct principle, formula, distractor logic and common mistake on that question page.
- Move one level in the graph: use the closest concept/sub-topic/topic link rather than opening unrelated content.
- Reattempt: solve another verified PYQ from this hub and check whether the same error repeats.
Quality scope: this page is automatically maintained from SRO’s verified mapped corpus. It enriches one canonical authority URL instead of generating multiple near-duplicate pages for keyword variants. Manual authority articles are never overwritten by the automated engine.