Download PTU B.Tech 2021 Jan EE 7th Sem 71931 High Voltage Engineering Question Paper

Download PTU (Punjab Technical University) B.Tech (Bachelor of Technology) / BE (Bachelor of Engineering) 2021 January EE 7th Sem 71931 High Voltage Engineering Previous Question Paper

Roll No.
Total No. of Pages : 02
Total No. of Questions : 18
B.Tech. (Electronics & Electrical)/(EE) (2012 Onwards)
B.Tech. (Electrical & Electronics)/ (Electrical Engineering) (Sem.?7)
HIGH VOLTAGE ENGINEERING
Subject Code : BTEE-802
M.Code : 71931
Time : 3 Hrs. Max. Marks : 60
INST RUCT IONS T O CANDIDAT ES :
1 .
SECT ION-A is COMPULSORY cons is ting of TEN questions carrying TWO marks
each.
2 .
SECT ION-B c ontains F IVE questions c arrying FIVE marks eac h and s tud ents
have to atte mpt any FOUR q ues tions.
3 .
SECT ION-C contains THREE questions carrying T EN marks e ach and s tudents
have to atte mpt any T WO questio ns.
SECTION-A
Write briefly :
1.
Define the insulation co-ordination.
2.
Define the critical HVDC voltage for corona.
3.
Explain the causes of RI generation in transmission line.
4.
Write any four disadvantage of HVDC transmission.
5.
Define the streamer theory of breakdown.
6.
Write any four name of insulating liquid used in high voltage equipments.
7.
Explain the term electron attachment in gases.
8.
What do you understand by intrinsic strength of a solid dielectric?
9.
Define the front and tail times of an impulse wave.
10. What is trigatron gap?
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SECTION-B
11. Explain why certain corona is inherent in new EHVAC lines and HVDC lines? Why
corona-loss lines are not practically possible?
12. Explain any two theories that explain breakdown in commercial liquid dielectrics.
13. Indicate the solid insulation application in a) cable b) power capacitor.
14. Explain the phenomenon treeing and tracking in solid insulating materials under electrical
stress. How does it lead to breakdown?
15. Discuss any methods of measuring high dc voltages and also discuss its limitations.
SECTION-C
16. Why is a Cock-Craft Walton circuit preferred for voltage multiplier circuits? Explain its
working with a schematic diagram.
17. a. Define Townsend's first and second ionization coefficients. How is the condition for
breakdown obtained in a Townsend discharge?
b. What will be the breakdown strength of air be for small gaps (1 mm) and large gaps
(20 cm) under uniform field conditions and standard atmospheric conditions?
18
Write short notes on the following :
a. Series and shunt compensation in EHV lines.
b. Measurement of impulse voltage.
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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