GTU BE 8th Semester 2182407 Switch Gear and Protection Summer 2018 Question Paper

1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE – SEMESTER ?VIII (NEW) – EXAMINATION ? SUMMER 2018
Subject Code: 2182407 Date: 07/05/2018
Subject Name: Switch Gear & Protection
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.

MARKS
Q.1 (a) Explain RRRV in brief. 03
(b) List the advantages of static relay. 04
(c) Explain the construction and working of air break circuit
breaker with neat diagram.
07

Q.2 (a) Explain any one methods of neutral grounding. 03
(b) Explain attracted armature relay. 04
(c) Explain air-blast circuit breaker with necessary diagrams. 07
OR
(c) Explain auto-reclosing in power system protection. 07
Q.3 (a) List the advantages of SF6 circuit breaker. 03
(b) Explain induction disc relay. 04
(c) Explain the construction and working principle of
Buchhoz relay.
07
OR
Q.3 (a) Derive the equation of restriking voltage. 03
(b) Discuss single line to ground fault. 04
(c) Explain Inter turn fault protection scheme for generator. 07
Q.4 (a) Explain the function of isolator. 03
(b) Compare induction disc and induction cup type relays. 04
(c) Write a short note on Directional relay. 07
OR
Q.4 (a) Draw different characteristics of distance relay. 03
(b) Explain percentage differential protection of transformer. 04
(c) Explain carrier current based transmission line protection
scheme with block diagram.
07
Q.5 (a) Draw the schematic diagram of single phase sub-station. 03
(b) Discuss current chopping with relevant diagrams. 04
(c) Difference between statics relay v/s electromagnetic relay. 07
OR
Q.5 (a) Explain the following term: (i) Switch-gear, (ii) Lightning
arrester and (iii) Earthing switch
03
(b) Explain the protection of generator against stator and rotor
faults.
04
(c) Explain the construction and working principle of zinc
oxide lightning arrester.
07