Dakshin Gujarat Vij Company Limited (DGVCL)

Dakshin Gujarat Vij Company Limited (DGVCL) – Verified PYQ Authority Guide

Dakshin Gujarat Vij Company Limited (DGVCL) is a recruiting-authority PYQ hub built only from verified exam mappings in SRO. It connects the authority’s mapped exams/papers with the subjects, topics and solved questions currently supported by the corpus. 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

28 verified PYQs are currently mapped to this Authority hub. The represented years include 2024. Exam coverage currently includes Vidyut Sahayak (Junior Engineer - Electrical). Subject context includes Electrical Engineering, Engineering Management. 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.

1. The per unit value of any quantity is defined as:
   Vidyut Sahayak (Junior Engineer - Electrical) · 2024 · Definition of Per-Unit Value
   C — Actual value divided by base value in the same units. The units cancel, making the per-unit quantity dimensionless.
2. Which of the following is not a valid three phase transformer connection?
   Vidyut Sahayak (Junior Engineer - Electrical) · 2024 · Transformer Vector Groups and Clock Notation
   A — Dd1. A conventional delta–delta transformer connection does not provide the 30° displacement required by clock number 1.
3. Find the value of current I in given fig.
   Vidyut Sahayak (Junior Engineer - Electrical) · 2024 · Ohm’s Law and Series Resistance
   B — 1 A. The 2 Ω and 6 Ω resistors are in series, so the 8 V source drives 8/(2 + 6) =…
4. What is the significance of power factor improvement in power systems?
   Vidyut Sahayak (Junior Engineer - Electrical) · 2024 · System Benefits of Power Factor Improvement
   D — It minimizes the reactive power burden on generators and transmission equipment. Local compensation reduces the reactive current carried upstream.
5. The lagging reactive power delivered by a line is proportional to ______ and is independent of ______.
   Vidyut Sahayak (Junior Engineer - Electrical) · 2024 · Reactive Power–Voltage Drop Relationship
   C — Line voltage drop; δ. This is the small-angle, predominantly reactive-line approximation; the exact reactive-power expression still contains cos δ.
6. What is the effect of present of salt on resistivity of soil?
   Vidyut Sahayak (Junior Engineer - Electrical) · 2024 · Effect of Salt Content on Soil Resistivity
   B — Resistivity decreases with increase in salt content. Dissolved salts add mobile ions to moist soil and increase its electrical conductivity.
7. Which of the following factor does not affect critical corona voltage while using bundled conductors?
   Vidyut Sahayak (Junior Engineer - Electrical) · 2024 · Factors Affecting Critical Corona Voltage
   B — Length of line. Corona inception depends on the local conductor-surface electric field, not the total length of an otherwise identical uniform line.
8. A 50 kW, 400 V, 3 phase synchronous motor is operating at full load with an efficiency of 90%. If the field current is adjusted to make its power factor 0.8 leading,…
   Vidyut Sahayak (Junior Engineer - Electrical) · 2024 · Three-Phase Motor Current from Output Power and Efficiency
   C — 100 A approximately. Electrical input is 50/0.90 = 55.56 kW, giving line current 55,555.56/(√3 × 400 × 0.8) = 100.23 A.

Formula & key-relationship bank from verified solutions

• xpu = xactual/xbasePercentage value = 100 × xpu
• Clock displacement = clock number × 30°Dd1 requires 30°; conventional Dd does not provide this displacement
• Rtotal = 2 + 6 = 8 ΩI = V/Rtotal = 8/8 = 1 A
• S = P/cos φIL = P/(√3 VLcos φ)Qcomp = P(tan φ1 − tan φ2)
• QR = (VSVR cos δ − VR²)/XFor small δ: QR ≈ VRΔV/X
• ρ = 1/σρ in Ω·m; σ in S/m

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

• C — Actual value divided by base value in the same units. The units cancel, making the per-unit quantity dimensionless.
• A — Dd1. A conventional delta–delta transformer connection does not provide the 30° displacement required by clock number 1.
• B — 1 A. The 2 Ω and 6 Ω resistors are in series, so the 8 V source drives 8/(2 + 6) = 1 A.
• D — It minimizes the reactive power burden on generators and transmission equipment. Local compensation reduces the reactive current carried upstream.
• C — Line voltage drop; δ. This is the small-angle, predominantly reactive-line approximation; the exact reactive-power expression still contains cos δ.

Exam tips already validated in SRO solutions

• Per unit is always actual ÷ base—not base ÷ actual.
• Clock number ×30° gives displacement. Same-connection groups such as Dd do not normally give 30° displacement.
• One loop, no branches → series resistance first, then one Ohm’s-law step.
• Fixed kW: current is inversely proportional to power factor.
• P–δ and Q–V is one of the most useful power-system approximation pairs.

Common mistakes to avoid

• Mixing units such as volts and kilovolts without converting them consistently before forming the ratio.
• Assuming any clock number 0–11 can be paired with any winding-connection letters.
• Using only the 2 Ω or only the 6 Ω resistor when computing current instead of adding both series resistances.
• Saying power-factor correction reduces the load’s real kW demand. It mainly reduces reactive demand and line current for the same useful real power.
• Treating the ‘independent of δ’ statement as exact under all operating conditions; it is an approximation associated with a predominantly reactive line and small δ.

Topic and concept coverage

Mapped topic labels include Earthing, FACTS Controllers, Risk Management, Transformers, Transmission Lines, Corrosion Protection, DC Circuits. The concept trail includes Balanced Earth-Fault Protection for Small Generators, Characteristic Equation and System Poles, Coefficient of Coupling Relation, Definition of Per-Unit Value, Earthing-Conductor Colour Coding, Effect of Salt Content on Soil Resistivity, Excitation and Variable-Speed Operation, Factors Affecting Critical Corona Voltage. 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, Vidyut Sahayak (Junior Engineer - Electrical), Electrical Engineering, Power Systems, Electrical Machines, Basic Electrical Engineering, Electrical Installation & Safety, Earthing. 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

1. Solve before reading: answer a mapped PYQ first.
2. Read the exact explanation: verify the correct principle, formula, distractor logic and common mistake on that question page.
3. Move one level in the graph: use the closest concept/sub-topic/topic link rather than opening unrelated content.
4. 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.