Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Summer 8th Sem Old 180903 Power System Practice And Design Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VIII (OLD) EXAMINATION ? SUMMER 2019
Subject Code: 180903 Date: 13/05/2019
Subject Name:Power System Practice And Design
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) How spacing between the conductors and voltage selection is carried out to
design the transmission line?
07
(b) Explain the phenomena of ?Corona Loss?. How is it calculated? 07
Q.2 (a) State & explain the Kelvin?s law to determine the economical size of conductor. 07
(b) A 3-core distribution cable is 250 meter long and supplies a load of 75 KW at
400 V at 0.8 power factor lag for 3000 Hrs in a year. The cable cost including
installation is Rs ( 12 a + 30) per meter where ?a? is the cross sectional area of
conductor in Sq. cm. Cost of energy wasted is 10 paisa per unit and the rate of
interest and depreciation is 10%. The resistance per Km of the conductor of 1
cm
2
cross section is 0.25 ?. Find the most economical cross section of the
distribution cable.
07
OR
(b) List out the different equipments used in sub-station. Explain the function of
each.
07
Q.3 (a) Explain Lamp-flickering. What are the causes and remedies of it? 07
(b) Explain the Gas-Insulated Substation. 07
OR
Q.3 (a) Compare HVDC & HVAC system. 07
(b) Draw the well-labeled diagram of HVDC system. 07
Q.4 (a) What are the important factors for designing extra high voltage transmission line? 07
(b) Discuss the important factors for the location of substation. 07
OR
Q.4 (a) Derive the necessary equation to calculate the sag in case of equal level of
transmitting tower.
07
(b) A 2-wire d.c. distribution AB is fed from both ends. At the feeder point A the
voltage is maintained at 240 V and at B 245 V. The total length of distributor is
200 meter and loads are tapped off as under. 20 A at 50 meter from A, 40 A at
75 meter from A, 23 A at 100 meter from A, 42 A at 150 meter from A. If the
resistance per Km of one conductor is 0.3 ?. Calculate the current in the various
section of the distributor.
07
Q.5 (a) Explain ?Touch? and ?Step? potential. How to measure soil resistivity? 07
(b) Explain factors to be considered for selection of size and location of generating
station.
07
OR
Q.5 (a) Explain the different types of DC distribution system. 07
(b) Give the comparison between Radial and Ring type distribution system. 07
*************
FirstRanker.com - FirstRanker's Choice
This post was last modified on 20 February 2020