Download VTU ((Visvesvaraya Technological University) B.E/B-Tech 2019 July ( Bachelor of Engineering) First & Second Semester (1st Semester & 2nd Semester) 2015 Jan 2014 Dec 14ELN15 Basic Electronics Question Paper
USN
14ELN15
Q
First Semester B.E. Degree Examination, Dec.2014/Jan.2015
Basic Electronics
Time: 3 hrs. Max. Marks:100
Note: Answer FIVE full questions, selecting
atleast ONE question from each part.
PART 1
1 a. Draw and explain the V-I characteristics of a silicon P-N junction Diode.. (05 Marks)
b. A single phase full - wave rectifier supplies power to a 1 K.Q load. The AC voltage applied
to the diode is 300 - 0 - 300 V. If diode resistance is 251) and that of the transformer
secondary negligible. Determine average load current, average load voltage and rectification
efficiency. (06 Marks)
c. Draw and explain the series negative clipper circuit with a suitable waveform. (04 Marks)
d. Derive an equation for the collector current of a P -N-P transistor in terms of base current
and
adc
and also obtain the relationship between adc and Nc. (05 Marks)
2 a. With a neat circuit diagram and waveform, explain the working of a half - wave rectifier
and show that its ripple factor is 1.21. (07 Marks)
b. Draw the common - emitter circuit and sketch the input and output characteristics. Also
explain operating regions by indicating them on the characteristic curve. (07 Marks)
c. Explain the performance of Zener -.Diode in terms of source and load effects. (06 Marks)
PART - 2
3 a. Explain the operation of a fixed - bias circuit, with a suitable circuit diagram. (07 Marks)
b. What are the ideal characteristics of a operational amplifier? (05 Marks)
c. A voltage - divider bias circuit has Vcc = 15 V, R
c
- 2.7 KO and RE = 2.2 KC), R
1
= 22 K.Q
"Rik
R2 = 12 Kn , life = 50. Calculate VE, Vc, lc and VcE and also draw DC load line and mark the
Q ? point. Assume VBE = 0.7 V.
(08 Marks)
4 a. Derive the expression of output voltage of a differentiator circuit using an opamp. (05 Marks)
b. Write expression for output voltage at points A, B, C, D and E as shown in Fig. 4(b).
(10 Marks)
I KJI.-
VLAAJ
Fig. Q4(b)
c. With a neat circuit diagram and waveform, explain how opamp can be used as a
non - inverting amplifier. (05 Marks)
1 oft
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USN
14ELN15
Q
First Semester B.E. Degree Examination, Dec.2014/Jan.2015
Basic Electronics
Time: 3 hrs. Max. Marks:100
Note: Answer FIVE full questions, selecting
atleast ONE question from each part.
PART 1
1 a. Draw and explain the V-I characteristics of a silicon P-N junction Diode.. (05 Marks)
b. A single phase full - wave rectifier supplies power to a 1 K.Q load. The AC voltage applied
to the diode is 300 - 0 - 300 V. If diode resistance is 251) and that of the transformer
secondary negligible. Determine average load current, average load voltage and rectification
efficiency. (06 Marks)
c. Draw and explain the series negative clipper circuit with a suitable waveform. (04 Marks)
d. Derive an equation for the collector current of a P -N-P transistor in terms of base current
and
adc
and also obtain the relationship between adc and Nc. (05 Marks)
2 a. With a neat circuit diagram and waveform, explain the working of a half - wave rectifier
and show that its ripple factor is 1.21. (07 Marks)
b. Draw the common - emitter circuit and sketch the input and output characteristics. Also
explain operating regions by indicating them on the characteristic curve. (07 Marks)
c. Explain the performance of Zener -.Diode in terms of source and load effects. (06 Marks)
PART - 2
3 a. Explain the operation of a fixed - bias circuit, with a suitable circuit diagram. (07 Marks)
b. What are the ideal characteristics of a operational amplifier? (05 Marks)
c. A voltage - divider bias circuit has Vcc = 15 V, R
c
- 2.7 KO and RE = 2.2 KC), R
1
= 22 K.Q
"Rik
R2 = 12 Kn , life = 50. Calculate VE, Vc, lc and VcE and also draw DC load line and mark the
Q ? point. Assume VBE = 0.7 V.
(08 Marks)
4 a. Derive the expression of output voltage of a differentiator circuit using an opamp. (05 Marks)
b. Write expression for output voltage at points A, B, C, D and E as shown in Fig. 4(b).
(10 Marks)
I KJI.-
VLAAJ
Fig. Q4(b)
c. With a neat circuit diagram and waveform, explain how opamp can be used as a
non - inverting amplifier. (05 Marks)
1 oft
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14ELN15
PART-3
5 a. State De Morgan's theorem for 4 ? variables and prove them by the method of perfect
( induction. (06 Marks)
b. Design full ? adder circuit using three ? variables and implement it using two half ? adder.
(06 Marks)
c. Explain the construction of an OR ? gate using diodes. (04 Marks)
d. Realize basic gates from NAND gate. (04 Marks)
6 a. Design a logic circuit, symbol, and truth ? table of exclusive ? OR gate. (04 Marks)
b. Convert
i) (294.6875)14 ? )
s
ii) (356.15)s ?.(
?( )10.
c. Simplify and Realize using basic gates :
i) ABC + ABC + ABC + ABC
4
ii) (A + B) (A +e) (T? + C) . (06 Marks)
d. Subtract (111)2 from (1010)2 using l's and 2's complement method. (05 Marks)
?
PART-1
6.
V", \
7 a. Explain the working of clocked R S flip ? flop with a suitable logic diagram and a
truth-table. (06 Marks)
b. Explain the logic pinout and signals of 8085 microprocessor. (08 Marks)
c. Explain the construction and working of a linear variable differential transducer [LVDT].
(06 Marks)
8 a. With a neat block diagram, explain the architecture of 8051 microcontroller.
b. What is a transducer?. Distinguish between active and passive transducer.
c. What is Thermister? Explain its advantages and limitations.
PART-5
(09 Marks)
(06 Marks)
(05 Marks)
m
2
9 a. Define amplitude modulation and prove that P
1
= Pc 1+-
2
. (05 Marks)
b. What are commonly used frequency ranges in communication system? Mention the
application of each range. (05 Marks)
c. The total power content of an AM signal is 1000 W. Determine the power being transmitted
at carrier frequency and at each of the side bands when percentage modulation is 100%.
(05 Marks)
d. Explain the differences between Amplitude and Frequency modulation. (05 Marks)
10 a. Explain the block diagram of ISDN. (06 Marks)
b. What are the advantages of optical fiber communication? (05 Marks)
c. Explain the basic principle of operation of mobile phones. (05 Marks)
d. What is modulation? Explain need of modulation. (04 Marks)
(05 Marks)
2 of 2
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This post was last modified on 01 January 2020