Power Systems & Transmission
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📘 Comprehensive Syllabus & Examination Guide
Power Systems & Transmission
Official curriculum roadmap, subject/topic distribution, negative marking rules, pacing guidelines, and solved sample questions.
🎯 Mapped Subjects & Topic Question Distribution
Total Question Pool
100%
30 MCQs
Combined Active Syllabus
Power Systems & Transmission
30 MCQs
Topic Pool
📊 Question Pool Structure
30 MCQs across fundamental, intermediate, and advanced concept tiers.
⚡ Recommended Pacing
45 to 60 seconds per MCQ. Flag complex problems and preserve 10 minutes for final revision.
⚖️ Scoring & Negative Marking
+1 mark per correct answer. In competitive tests with negative marking, -0.25 applies for incorrect guesses.
💡 Strategic Preparation & Exam Hall Guidelines
To maximize your score on Power Systems & Transmission, candidates are advised to follow a structured three-pass approach. In the First Pass, solve all direct recall and formula-based questions within 30 seconds each to secure foundational marks. In the Second Pass, tackle multi-step analytical and quantitative reasoning problems. In the Third Pass, review marked questions and verify calculations.
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Solved Blueprint Examples
Showing 10 solved representative questions
📝 Pre-Rendered Solved Sample Questions & Detailed Solutions
Review the solved problems below to understand question phrasing, answer choices, and step-by-step solution logic prior to starting the full interactive practice drill:
Sample Question 1
Power Systems & Transmission
Easy • Electrical Engineering
The Ferranti Effect in electrical power transmission lines refers to the phenomenon where:
A
The receiving-end voltage is higher than the sending-end voltage under no-load or lightly loaded conditions on long transmission lines
B
The line voltage drops significantly during heavy inductive loading
C
Current concentrates on the outer surface of conductors
D
Corona discharge ionizes ambient air at high altitudes
✓ Correct Answer: A - The receiving-end voltage is higher than the sending-end voltage under no-load or lightly loaded conditions on long transmission lines
📖 Step-by-Step Solution & Conceptual Rationale:
On long, lightly loaded or open-ended transmission lines, line charging current flowing through the line's distributed series inductance causes a voltage rise along the line, resulting in receiving-end voltage exceeding sending-end voltage (Vr > Vs). Shunt reactors are installed to absorb this reactive power.
Sample Question 2
Power Systems & Transmission
Easy • Electrical Engineering
Surge Impedance (or characteristic impedance Zc) of a lossless overhead transmission line with inductance L and capacitance C is given by:
A
Zc = sqrt(L / C)
B
Zc = sqrt(C / L)
C
Zc = 1 / sqrt(L * C)
D
Zc = sqrt(L * C)
✓ Correct Answer: A - Zc = sqrt(L / C)
📖 Step-by-Step Solution & Conceptual Rationale:
For a lossless line (R=0, G=0), the surge impedance is Zc = sqrt(L / C). For typical overhead transmission lines, Zc ranges from 400 to 450 ohms, while for underground cables, Zc is around 40 to 50 ohms.
Sample Question 3
Power Systems & Transmission
Medium • Electrical Engineering
Surge Impedance Loading (SIL) of a transmission line with nominal line-to-line voltage V_LL and surge impedance Zc is:
A
SIL = V_LL^2 / Zc
B
SIL = Zc / V_LL^2
C
SIL = sqrt(3) * V_LL * Zc
D
SIL = V_LL * Zc
✓ Correct Answer: A - SIL = V_LL^2 / Zc
📖 Step-by-Step Solution & Conceptual Rationale:
Surge Impedance Loading represents the power delivered by a transmission line to a load equal to its surge impedance: SIL = V_LL^2 / Zc (MW). At this loading, reactive power generated by line capacitance exactly balances reactive power absorbed by line inductance, yielding flat voltage along the line.
Sample Question 4
Power Systems & Transmission
Easy • Electrical Engineering
Corona discharge on high-voltage overhead transmission lines is accompanied by:
A
A violet-colored luminous glow, hissing noise, ozone gas production, and power loss
B
Sudden freezing of line conductors
C
Complete cancellation of series line inductance
D
Zero power loss
✓ Correct Answer: A - A violet-colored luminous glow, hissing noise, ozone gas production, and power loss
📖 Step-by-Step Solution & Conceptual Rationale:
Corona occurs when the electrostatic field gradient at the conductor surface exceeds the dielectric breakdown strength of air (approx. 30 kV/cm peak or 21.2 kV/cm RMS). Ionization of air produces a faint violet glow, hissing acoustic noise, chemical production of ozone (O3), and power loss.
Sample Question 5
Power Systems & Transmission
Medium • Electrical Engineering
Bundle conductors are widely employed in Extra High Voltage (EHV) and Ultra High Voltage (UHV) transmission lines primarily to:
A
Increase the effective conductor diameter (GMR), thereby reducing surface electric field gradient, corona loss, and line reactance
B
Make tower erection easier and cheaper
C
Eliminate the need for lightning arresters
D
Prevent mechanical sag in hot summers
✓ Correct Answer: A - Increase the effective conductor diameter (GMR), thereby reducing surface electric field gradient, corona loss, and line reactance
📖 Step-by-Step Solution & Conceptual Rationale:
Using bundles of two, three, or four sub-conductors per phase increases the Geometric Mean Radius (GMR) of the phase conductor. This lowers the electrostatic surface stress below the critical disruptive threshold, substantially reducing corona loss, radio interference, and series inductive reactance.
Sample Question 6
Power Systems & Transmission
Medium • Electrical Engineering
The critical disruptive voltage of a transmission line decreases under which environmental condition?
A
High atmospheric pressure and dry air
B
Stormy, foul weather (rain, fog, or snow) and high altitude with low barometric pressure
C
Sub-zero temperatures with dry breeze
D
Nighttime with clear skies
✓ Correct Answer: B - Stormy, foul weather (rain, fog, or snow) and high altitude with low barometric pressure
📖 Step-by-Step Solution & Conceptual Rationale:
Critical disruptive voltage Vd = m0 * g0 * delta * r * ln(D/r). At high altitudes or stormy weather, the air density factor delta decreases and the conductor irregularity factor m0 drops from 1.0 to ~0.8, causing corona to initiate at much lower voltages.
Sample Question 7
Power Systems & Transmission
Medium • Electrical Engineering
The proximity effect in transmission conductors refers to:
A
Current redistribution due to the magnetic fields of nearby conductors carrying current, increasing effective AC resistance
B
Mutual capacitance between tower body and ground wire
C
The reflection of lightning traveling waves
D
Thermal heating of insulators
✓ Correct Answer: A - Current redistribution due to the magnetic fields of nearby conductors carrying current, increasing effective AC resistance
📖 Step-by-Step Solution & Conceptual Rationale:
Proximity effect occurs when alternating flux from an adjacent parallel conductor distorts the current distribution across the cross-section of a conductor. When currents flow in the same direction, current shifts away from adjacent sides; when in opposite directions, it concentrates on facing sides, raising AC resistance.
Sample Question 8
Power Systems & Transmission
Easy • Electrical Engineering
ACSR (Aluminum Conductor Steel Reinforced) conductors are standard for overhead transmission because:
A
The inner steel core provides high mechanical tensile strength, while outer aluminum strands provide high electrical conductivity and lighter weight
B
Steel has higher electrical conductivity than aluminum
C
Aluminum prevents mechanical corrosion of steel completely
D
Steel reduces eddy current losses to zero
✓ Correct Answer: A - The inner steel core provides high mechanical tensile strength, while outer aluminum strands provide high electrical conductivity and lighter weight
📖 Step-by-Step Solution & Conceptual Rationale:
Pure aluminum has high conductivity and low weight but low tensile strength. Combining a high-tensile galvanized steel core with surrounding aluminum strands gives ACSR high mechanical strength to permit long spans between towers with reduced sag.
Sample Question 9
Power Systems & Transmission
Medium • Electrical Engineering
String efficiency of a suspension insulator string on an overhead transmission tower is defined as:
A
Total flashover voltage / Breakdown voltage
B
Voltage across the whole string / (Number of insulator discs * Voltage across the disc nearest to the line conductor)
C
Capacitance of top disc / Capacitance of bottom disc
D
Leakage resistance / Surface resistance
✓ Correct Answer: B - Voltage across the whole string / (Number of insulator discs * Voltage across the disc nearest to the line conductor)
📖 Step-by-Step Solution & Conceptual Rationale:
Due to shunt capacitance between insulator metal pins and the grounded tower body, voltage distribution across the string is non-uniform, with the bottom disc (nearest the line conductor) experiencing the greatest electrical stress. String efficiency = V_total / (n * V_bottom) * 100%.
Sample Question 10
Power Systems & Transmission
Medium • Electrical Engineering
A guard ring (static shielding ring) is installed around the bottom disc of an insulator string to:
A
Improve string efficiency by introducing cross-capacitances that equalize the voltage distribution across all discs
B
Provide mechanical support to line clamps
C
Prevent birds from perching on the line
D
Ground lightning strikes directly to the tower
✓ Correct Answer: A - Improve string efficiency by introducing cross-capacitances that equalize the voltage distribution across all discs
📖 Step-by-Step Solution & Conceptual Rationale:
A guard ring introduces capacitance between the line conductor and the insulator pins. These currents counteract the pin-to-ground leakage currents, making the voltage distribution across all discs nearly uniform, raising string efficiency close to 100%.
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