August
V62/T04061/EE/20150811
2015
Power Electronics
Instructions:
Marks-80
Time: 3 Hrs
1. All questions are compulsory.
2. “Long Answer type Question (LAQ)” is a supply type
question of 15 marks which required a typical answer of about
60-80 lines in bout 32-40 minutes.
3. “Sort Answer type Question (SAQ)” is a supply type question
of 5 marks which required a typical answer of about 15-20 lines
in bout 08-10 minutes.
4. Figures to the right indicate marks allotted to the questions.
5. Assume suitable data if necessary
6. Use a nonprogrammable type of scientific calculator is
allowed
Marks
SECTION-A
Q.1 Explain SCR Rating with details of current rating & voltage rating.
What is the function of the drift layer in power BJT?
15
OR
Q.1 State Merits, Demerits & Application of Power BJT (five points for
merits, five points for demerits & five point’s applications).
15
Q.2 Explain Class E & Line commutation turn off methods with neat
circuit diagram & waveform of it .Compare forced & natural
commutation of SCR (3 points).
15
OR
Q.2 Explain how SCR can be turn off naturally? Draw & explain the
turn off characteristics of an SCR. In which factors the turn off time
depends.
15
Q.3 Define GTO & IGBT explain its construction.
5
Q.4 Draw & explain I-V characteristics of SUS.
5
SECTION-B
Q.5 Define the term Semi converters. List any four advantages &
application of Semi converters. Draw the different configuration of
single phase half controlled bridge rectifier.
15
OR
Q.5 Compare full wave controlled rectifier & half wave controlled
rectifier (any 6 points). List any five advantages & type of
polyphone rectifier.
15
Q.6 What is an inverter? Draw neat circuit diagram of series & parallel
inverters, explain operation & any three performance parameter of
inverters.
15
OR
Q.6 State the important specification of OFF line & ON line UPS. State
the application of UPS.
15
Q.7 With the help of circuit diagram explain the operation of simple
battery charger.
5
Q.8 Why semi converter is preferred over full converter where
regenerating braking is not required?
5
Computer Generated Random Question Paper dated: 07-07-2015 15:36:04
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