Gujarat Technological UniversitySummer 2025 examination

GTU 3150911 Power System- II Summer 2025 Question Paper & PDF

B.E. · Electrical Engineering · Semester 5 · Subject code 3150911
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Total
70 marks
To pass
23 marks (33%)
Duration
2.5 Hours 2:30 PM – 5:00 PM
Questions
5 with internal choice
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11 of 25 questions on this paper were also asked in other years. 2 more are types of question GTU sets again with new data. Each is marked below with the years it appeared.See all 27 repeated 3150911 questions, most asked first

Q.1

14 Marks
(a)
3 marksAsked in 2 of 4 papers
What is the per-unit system? Give the advantages of the per-unit system.

Also asked in Summer 2026 Q1a

(b)
4 marks

What is the balanced three-phase power? Prove that under balance conditions, the sum of phasors is zero.

(c)
7 marksSame type asked in 2 of 4 papers

A 3-phase, 11kV, 15 km length, transmission line supplying a load of 850 kW at 0.8 power factor lagging, has resistance (R)= 0.45 Ω/km and reactance

x)= 0.60 Ω/km. Calculate,
i)the line current,
ii)receiving end voltage,
iii)voltage regulation, and
iv)the efficiency of power transmission.

Also asked in Summer 2023 Q1b, Summer 2023 Q4b

Q.2

14 Marks
(a)
3 marksAsked in 2 of 4 papers

Explain in detail the sub-transient, transient, and steady-state reactance by drawing a proper transient wave.

Also asked in Summer 2026 Q3b OR

(b)
4 marks

Obtain the equivalent circuit of the medium transmission line using nominal-π (PI) representation.

(c)
7 marks
Explain the working of a synchronous generator connected to an infinite bus.

Draw equivalent circuit and phasor diagram.

(c)
7 marks
A 275kV transmission line has the following line constants:

A = 0.85∠5°, B = 200∠75° Determine the power at unity power factor that can be received, if the voltage profile at each end will be maintained at 275 kV.

Q.3

14 Marks
(a)
3 marksAsked in 2 of 4 papers

What is fault? Classify various types of fault conditions of power system. Give the significance of the fault impedance.

Also asked in Winter 2023 Q5a

(b)
4 marks
Explain salient pole synchronous generator with power angle curve in short.
(c)
7 marksAsked in 2 of 4 papers

Give the analysis of double line to ground fault considering the effect of fault impedance.

Also asked in Summer 2023 Q4c

(a)
3 marksAsked in 2 of 4 papers
Show that symmetrical component transformation is power invariant.

Also asked in Summer 2023 Q3a

(b)
4 marksAsked in 2 of 4 papers

Derive the necessary equations to obtain symmetrical components from the phase quantities.

Also asked in Winter 2023 Q5b

(c)
7 marksAsked in 4 of 4 papers

Explain the zero-sequence impedance of the transformer for various connections.

Also asked in Summer 2026 Q3c, Winter 2023 Q5b OR, Summer 2023 Q4a

Q.4

14 Marks
(a)
3 marksAsked in 3 of 4 papers
What is insulation coordination? Define and explain BIL.

Also asked in Summer 2026 Q4b, Winter 2023 Q1a

(b)
4 marksAsked in 2 of 4 papers

Explain in brief the different methods of voltage control employed in power systems.

Also asked in Summer 2023 Q5b

(c)
7 marksAsked in 3 of 4 papers
Explain types of lightning strokes.

Also asked in Summer 2026 Q4c OR, Summer 2023 Q5c OR

(a)
3 marks

Justify, that for a fault at alternator terminals, a single line-to-ground fault is generally more severe than a three-phase fault.

(b)
4 marksAsked in 3 of 4 papers
Explain various factors affecting Corona effect of the transmission line.

Also asked in Summer 2026 Q5b, Winter 2023 Q2c

(c)
7 marksSame type asked in 3 of 4 papers

Find the critical disruptive voltage and corona loss for a 3-phase line that is operating at 220 kV, 50 Hz frequency. The line has a conductor of 1.5 cm diameter arranged in a 3-meter delta connection. Assume air density of 1.05 and dielectric strength of air to be 21.1 kV/cm.

Also asked in Winter 2023 Q2c OR, Summer 2023 Q4b OR

Q.5

14 Marks
(a)
3 marks

Define surge impedance and explain the surge impedance loading of the transmission line.

(b)
4 marks
Explain any two causes which are producing transients on a transmission line.
(c)
7 marks
Write a note on the following:
1)Lightning Arresters
2)Surge absorber
(a)
3 marks
Write a brief note on capacitance switching.
(b)
4 marks
Define the following terms
i)transient
ii)restriking
iii)recovery voltage.
(c)
7 marks

Explain in brief the traveling waves of the transmission line when the receiving end is short-circuited.

More Power System- II papers

Questions repeat across sessions. Working through two or three papers shows you which topics GTU asks most.

Summer 202670 marks · 5 questions · Solved
Winter 202570 marks · 5 questions
Winter 202470 marks · 5 questions
Summer 202470 marks · 5 questions

Other Semester 5 subjects

BE Electrical

3150910
Electrical Machine- II
3150912
Signals and Systems
3150913
Disaster Management

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About this paper

Official Gujarat Technological University (GTU) examination paper for Power System- II (Summer 2025, B.E. · Electrical Engineering, Sem 5). Features complete 70-mark regular & remedial examination pattern, official marking distribution across all 5 questions, and direct 1-click official PDF download.

Transcribed for student exam preparation from Gujarat Technological University official examination archives. Questions, syllabus guidelines, and curriculum marking schemes remain the intellectual property of Gujarat Technological University.

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