18ELN14/24
Visvesvaraya Technological University, Belagavi
MODEL QUESTION PAPER
1st/2nd Semester, B.E (CBCS 2018-19 Scheme)
Course: 18ELN14/24- BASIC ELECTRONICS Set no. 2
Time: 3 Hours Max. Marks: 100
Note: Answer Five full questions selecting any one full question from each Module.
Question on a topic of a Module may appear in either its 1st or/and 2nd question.
Module-1 Marks
1
a. Explain the operation of PN junction diode under forward and reverse bias conditions 6M
b.
A full wave bridge rectifier with an input of 100V(rms) feeds a load of 1kΩ .VΩ .VT=0.7V
If the diodes employed are of silicon, what is the dc voltage across the load?
Determine the PIV rating of each diode..
Determine the maximum current that each diode conducts and the diode power rating.
6M
c.
Write a short note on
Light emitting diode and Photo coupler
8M
OR
2
a. What is Zener diode? With neat circuit diagram, explain the operation of a voltage regulator with and
without load?
8M
b. A silicon diode has IS=10nA operating at 25°C. Calculate In for a forward bias of 0.6V. 4M
c.
Define rectifier. SkΩ .Vetch a centre tapped full wave rectifier and derive the following. Show the
appropriate waveforms.
Average Voltage Efficiency and Ripple factor
8M
Module-2
3
a. Explain the construction and operation of JFET with necessary diagram. 7M
b. Draw and explain the V-I characteristics of SCR. 6M
c. With neat circuit diagram, explain the workΩ .Ving of CMOS inverter. 7M
OR
4
a. What is MOSFET? Explain MOSFET and MOSFET transfer characteristics. 8M
b. A certain JFET has an IGSS of -2nA for VGS= -20V Determine the input resistance. 4M
c. What is SCR? Explain the workΩ .Ving of two transistor model of SCR. 6M
Module-3
5 a. Describe the characteristics of basic Op-Amp. List out its ideal characteristics. 8M
b. A certain op-amp has an open loop voltage gain of 1,00,000 and a common mode gain of 0.2.
Determine the CMRR and express it in decibels. 4M
c. Derive the output voltage for the following
Integrator and Voltage follower
8M
OR
6
a.
Explain the following terms related to op-amp
CMRR Offest Voltage and Current Slew rate and Input bias
8M
b. Design an adder using op-amp to give the output voltage VO= [2V1+3V2+5V3]. 6M
c. Derive the output voltage of a non-inverting amplifier. 6M
Module-4
7
a. What is an amplifier? Explain the operation of transistor amplifier circuit. 8M
b. Define feedbackΩ .V amplifier? With necessary diagram and equation explain the different types of
feedbackΩ .V? 12M
OR
8
a. Briefly explain how a transistor is used as an electronic switch. 6M
b. Explain how 555 timer can be used as an oscillator. 6M
c. Define an oscillator? Derive the equation for Wien bridge oscillator. 8M
Module-5
9
a.
Perform the following
Convert B C D)16
Subtract using compliment method.
5M
b. Realize Y=AB+CD+E using NAND gates. 4M
c. What is a flip flop? Explain the Master Slave JK flip flop operation. 5M
d. With a neat blockΩ .V diagram explain GSM system. 6M
OR
10
a.
Perform the following
Convert (111110101101)2 to
Subtract using and compliment method. 5M
b. Design full adder circuit using three variables and implement it using two half adders. 8M
c. What is a counter? With a neat timing and blockΩ .V diagram, explain three bit asynchronous counter
operation. 7M