Electronics Engineering (Semester 3)
Total marks: 80
Total time: 3 Hours
INSTRUCTIONS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Draw neat diagrams wherever necessary.
Solve any four
1.a.
Explain working of pn junction diode and its V-I characteristics.
(5 marks)
00
1.b.
What is early effect in BJT?
(5 marks)
00
1.c.
Explain Zener diode as a voltage regulator.
(5 marks)
00
1.d.
Write short note on Tunnel diode.
(5 marks)
00
1.e.
Draw output waveform for the circuit given below.
(5 marks)
00
2.a.
Explain construction and working of solar cell and LED.
(10 marks)
00
2.b.
Find Q point if $\beta = 120 $. Also draw dc load line
(10 marks)
00
3.a.
Explain with construction working and characteristic operation of n-channel D-MOSFET. Also compare it with E-MOSFET.
(10 marks)
00
3.b.
Calculate dc load voltage, an ac ripple in output and ripple factor.
(10 marks)
00
4.a.
Find
Zi,
Zo,
Av and $A_{vs}$ using Hybrid -$\Pi$ model $(V_{BE} = 0.7 V, \beta = 100)$
(10 marks)
00
4.b.
Explain working of Full wave rectifier with LC filter. Also draw output waveforms and derive expression for ripple factor.
(10 marks)
00
5.b.
Design single stage CE amplifier for $Av \geq 180 , h_{fe}= 220 , V_{CC}= 18 V, h_{ie}= 2.7 K , S_{ICO} \leq 10 , f_{i} \leq 20Hz , V_{CE sat}= 1V , V_{BE}= 0.7 V.$ $h_{re}= h_{oe}= 0$
(15 marks)
00
5.b.
Explain positive and negative clampers.
(5 marks)
00
6.a.
FInd $I_{DQ}$ ,$ V_{DSQ}$ and $V_{GSQ}$ if $VGS_{TH} = 5 V$ , $I_{D ON} = 3mA$ and$ V_{GS ON} = 10 V$
(10 marks)
00
6.b.
Compare CE,CB and CC configuration of BJT amplifier.
(10 marks)
00