Power System-I 2022 Question Paper — Government College of Engineerin…
The 2022 Power System-I previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.
- University: Government College of Engineering and Technology, Jammu
- Subject: Power System-I
- Course: Power System - I
- Branch: Electrical Engineering
- Year: 2022
- Paper: end-term
- Duration: 180 minutes
- Total marks: 75
Instructions
- Attempt five questions in all, selecting at least two questions from each section.
- Assume suitable data wherever missing.
- Use of calculator is allowed
Questions
Section - A
- Q1.a. Explain the basic strcutre of a power system with the help of a neat diagram. [8 marks]
- Qb. What are essential components of a typical distribution system? Explain each of components in brief. [7 marks]
- Q2.a. Derive an expression for the power loss in an uniformly loaded D.C. distributor fed at both end with equal voltages. [8 marks]
- Qb. A 2-wire d.c. street mains AB, 600m long is fed from both ends at 220 V, Loads of 20A, 40A, 50A and 30A are tapped at distances of 100m, 250m, 400m and 500 m from the end A respectively. If the area of X-section of distributor conductor is $1\text{ cm}^2$, find the minimum consumer voltage. Take $\rho = 1.7 \times 10^{-6}\ \Omega\text{ cm}$. [7 marks]
- Q3.a. Show that the inductance per unit length of an overhead line due to internal flux linkages is constant and is independent of size of conductor. [8 marks]
- Qb. Derive an expression for inductance of 3-phase line having stranded conductor with equilateral spacing. [7 marks]
- Q4.a. Briefly discuss different types of conductors used for overhead a.c. transmission lines. [7 marks]
- Qb. What do you mean by interference of power lines with communication lines? Discuss various electromagnetic effects of power lines on communication lines. [8 marks]
Section - B
- Q5.a. Draw phasor diagram for nominal \pi-circuit of a transmission line. Derive expression for sending end voltage and current. [8 marks]
- Qb. A single phase overhead transmission line delievers 100 kW at 33 KV at 0.8 p.f. lagging. The total resistance and inductive reactance of the line are $10\ \Omega$ and $15\ \Omega$ respectively. Determine: i. Sending end voltage ii. Sending end power factor iii. Transmission efficiency [7 marks]
- Q6.a. Derive for a long line the sending end volatge and current relations in terms of receiving end voltage and current and the parameters of the line. [8 marks]
- Qb. What is Ferranti effect? Explain it with the help of phasor diagram. [7 marks]
- Q7.a. Describe briefly,with neat sketches,two types of insulator that are commonly used in overhead line.Discuss their merits and limitations. [8 marks]
- Qb. A string of eight suspension insulators is to be fitted with a grading ring. If the pin to earth capacitances is all equal to C, find the values of line to pin capacitances that would give a uniform voltage distribution over the string. [7 marks]
- Q8.a. What are the advantages and disadvnatges of corona? Explain the methods of reducing corona effect. [7 marks]
- Qb. Explain and make clear difference between visual and critical disruptive voltage. [8 marks]