Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Summer 7th Sem Old 171002 Power Electronics Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VII (OLD) EXAMINATION ? SUMMER 2019
Subject Code: 171002 Date: 14/05/2019
Subject Name:Power Electronics
Time: 02:30 PM TO 05:00 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) Define the following:- 08
(1) Reverse recovery Charge (2) Latching Current (3) Holding Current (4) Softness Factor
(b) Draw the symbols, V-I characteristics and give one application of following devices:
(1) IGBT (2) GTO (3) TRIAC
06
Q.2 (a) Explain operation of series connected thyristors in detail. 07
(b) Explain parallel operation of thyristor in detail. 07
OR
(b) Explain the operation of DC Chopper?s principal of operation 07
Q.3 (a) Briefly discuss switching behavior of a GTO 07
(b) Discuss Pulse Width Modulated Inverter 07
OR
Q.3 (a) Compare single phase half wave controlled bridge rectifier with Resistive load
(symmetrical configuration) from single phase half controlled bridge rectifier with
Resistive Inductive load (symmetrical configuration) using the following asked
performance parameter:- [Sketch must be neatly drawn].
1) Average load voltage along with waveform
2) Average load current along with waveform
07
(b) A highly inductive d.c. load requires 12A at 150V from 230V single phase a.c. supply. Give
the design details for this requirement using B-2 connection for ?=30?. Assume each SCR
to have a voltage drop of 1.5 V. Draw the respective waveforms of load voltage and load
current.
07
OR
Q.4 (a) Derive an expression for :-
a) Average load voltage
b) Average load current
c) RMS load voltage
For bi-phase half wave circuit with resistive load. Compare the waveforms of the same
circuit with resistive and inductive load for the given firing angles of 60?, 90?, 150?.
07
(b) Compare dielectric heating and induction heating 07
FirstRanker.com - FirstRanker's Choice
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VII (OLD) EXAMINATION ? SUMMER 2019
Subject Code: 171002 Date: 14/05/2019
Subject Name:Power Electronics
Time: 02:30 PM TO 05:00 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) Define the following:- 08
(1) Reverse recovery Charge (2) Latching Current (3) Holding Current (4) Softness Factor
(b) Draw the symbols, V-I characteristics and give one application of following devices:
(1) IGBT (2) GTO (3) TRIAC
06
Q.2 (a) Explain operation of series connected thyristors in detail. 07
(b) Explain parallel operation of thyristor in detail. 07
OR
(b) Explain the operation of DC Chopper?s principal of operation 07
Q.3 (a) Briefly discuss switching behavior of a GTO 07
(b) Discuss Pulse Width Modulated Inverter 07
OR
Q.3 (a) Compare single phase half wave controlled bridge rectifier with Resistive load
(symmetrical configuration) from single phase half controlled bridge rectifier with
Resistive Inductive load (symmetrical configuration) using the following asked
performance parameter:- [Sketch must be neatly drawn].
1) Average load voltage along with waveform
2) Average load current along with waveform
07
(b) A highly inductive d.c. load requires 12A at 150V from 230V single phase a.c. supply. Give
the design details for this requirement using B-2 connection for ?=30?. Assume each SCR
to have a voltage drop of 1.5 V. Draw the respective waveforms of load voltage and load
current.
07
OR
Q.4 (a) Derive an expression for :-
a) Average load voltage
b) Average load current
c) RMS load voltage
For bi-phase half wave circuit with resistive load. Compare the waveforms of the same
circuit with resistive and inductive load for the given firing angles of 60?, 90?, 150?.
07
(b) Compare dielectric heating and induction heating 07
2
OR
Q.4 (a) With an appropriate power diagram, discuss the principle of working of three phase
bridge inverter. Draw phase and line voltage waveforms on the assumption that each
thyristor conducts for 180?and resistive load is star connected.
07
(b) With the help of a neat circuit diagram and associated waveforms, discuss the operation of
Buck-Boost converter. List the advantages and disadvantages of this type of converter.
07
Q.5 (a) With the help of basic structural diagram explain the operation of DIAC and TRIAC 07
(b) Enlist and explain the performance parameters of Inverters 07
OR
Q.5 (a) Describe switched mode power supply with necessary details using diagram 07
(b) Explain battery charger with necessary diagrams 07
*************
FirstRanker.com - FirstRanker's Choice
This post was last modified on 20 February 2020