Power System Engineering-I SPPU Endsem Question Paper May 2025
All 8 questions from this SPPU endsem paper, as printed. Read them here or open the PDF.
- Subject code
- 203145
- Pattern
- 2019 pattern
- Exam
- Endsem
- Session
- May 2025
- Max. marks
- 70
- Time
- 2½ Hours
- Semester
- IV
- Paper code
- [6402]-16
Printed for: S.E. (Electrical)
Instructions to the candidates
- Attempt Q.1 or Q.2, Q.3 or Q.4, Q.5 or Q.6, Q.7 or Q.8.
- Figures to the right indicate full marks.
- Assume suitable additional data, if necessary.
- Draw neat & clean diagrams if necessary.
- Use of non-programmable calculator is allowed.
Questions
Q1
- a)[4]
Define span length. State the factors to be consider for selection of span length.
- b)[6]
Discuss any two types of line supports used in overhead lines and their advantage and disadvantages.
- c)[8]
A transmission line has a span of 150 m between level supports. The conductor has a cross-sectional area of 2cm 2 . The tension in the conductor is 2000 kg. If the specific gravity of the conductor material is 9.9 gm/cm 3 and wind pressure is 1.5 kg/m length, Calculate i) sag ii) vertical sag.
OR- a)
Q2
- a)[4]
Define pin type and shackle type insulator with their application.
- b)[6]
Describe any two methods for improving string efficiency in overhead line insulators.
- c)[8]
In a 33 kV overhead line, there are three units in the string of insulators. If the capacitance between each insulator pin and earth is 11% of self- capacitance of each insulator, find (i) Voltage across string (ii) the distribution of voltage over 3 insulators and (iii) string efficiency.
- a)
Q3
- a)[3]
State skin effect, enlist the factors responsible for skin effect.
- b)[6]
A single phase line has two parallel conductors 2m apart. The diameter of each conductor is 1.2cm. Calculate the loop inductance per km of the line.
- c)[8]
Derive an expression for flux linkages due to single current carrying conductor. 2
OR- a)
Q4
- a)[3]
Define concept of self and mutual G.M.D.
- b)[6]
Calculate the inductance of each conductor in a 3-phase, 3-wire system when the conductors are arranged in horizontal plane with spacing such that D 31 = 4m, D 12 = D 23 = 2m. The conductors are transposed and have a diameter of 2.5cm.
- c)[8]
Derive an expression for the inductance of three phase overhead transmission line with symmetrical spacing considering transposition.
- a)
Q5
- a)[4]
What is the need of transposition for capacitance calculation?
Also asked:Nov 2025
- b)[6]
A 3-phase overhead transmission line has its conductors arranged at the corners of an equilateral triangle of 2 m side. The diameter if each conductor is 1.25cm. Calculate capacitance of each line conductor per km.
- c)[8]
Derive the expression of capacitance of 3-phase overhead line with unsymmetrical spacing considering transposition.
Also asked:Nov 2024
OR- a)
Q6
- a)[4]
Explain the concept of G.M.R. for capacitance calculation.
- b)[6]
- c)[8]
A 3-phase, 50 Hz, 66kV overhead line conductors are placed in horizontal line. The conductor diameter is 1.25 cm. If the line length is 100km, Calculate capacitance per phase.
- a)
Q7
- a)[3]
Classify transmission lines based on length and voltage levels.
Also asked:Nov 2025
- b)[6]
Obtain the relationship between sending end voltage and current in terms of rcceiving end voltage and current for a medium transmission line using ‘nominal T’ method. Draw a neat phasor diagram.
- c)[8]
A 3-phase, 50 Hz, 150 km line has a resistance, inductive reactance and capacitive shunt admittance of 0.1 0.5 and 3 X 10-6 per km per phase. If the line delivers 50 MW at 110kV and 0.8 p.f. lagging, determine the sending end voltage and current. Assume a nominal circuit for the line. 3
OR- a)
Q8
- a)[3]
State and explain in short Ferranti effect?
- b)[6]
- c)[8]
An overhead 3-phase transmission line delivers 5000 kW at 22 kV at 0.8 p.f. lagging. The resistance and reactance of each conductor is 4 and 6 . Respectively. Determine i) sending end voltage ii) percentage regulation iii) transmission efficiency. JJJ
- a)