PTU Punjab Technical University B-Tech May 2019 Question Papers 6th Semester Electronic and Communication Engineering (ECE)
Total No. of Pages : 02
Total No. of Questions : 09
B.Tech.(ECE/ETE) (E-I 2011 Onwards) (Sem.?6)
Subject Code : BTEC-903
M.Code : 71232
Time : 3 Hrs. Max. Marks : 60
INSTRUCTIONS TO CANDIDATES :
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.
Answer briefly :
a) List various Chopper commutation methods.
b) What is form factor in case of half wave rectifier?
c) What is intrinsic standoff ratio? Also, give its range.
d) What is significance of duty cycle in case of choppers?
e) Differentiate voltage and current driven inverters.
f) Give applications of cycloconverter.
g) How can an UJT used for triggering of an SCR?
h) How firing angle effects the output voltage of converter?
i) What is commutator-less dc motor control?
j) How Power MOSFET differs from simple MOSFET?
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What do you mean by closed loop control? How can it be used in speed control of
Explain the two-transistor model of thyristor with suitable diagram.
Draw and explain the circuit of a parallel inverter.
What is the need of series and parallel connection of SCR? Explain the series connections
Discuss any three harmonic reduction techniques in PWM.
Explain any four techniques to turn-on the thyristor.
Explain the circuit of a single-phase full wave converter with RL load and with
freewheeling diode. Draw the waveforms at the output and across the diodes.
What do you mean by AC voltage controller? Explain sequence control of AC voltage in
case of single phase voltage controller.
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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This post was last modified on 04 November 2019