Maharashtra State Board of Technical Education 2012-4th Sem Diploma Mechanical Engineering for Subject Fundamental of Electronics (12090) - Question Paper

12090
11122
3 Hours / 100 marks

Instructions:
1. All ques. are compulsory.
2. presume suitable data, if necessary.
3. Figures to the right indicate full marks.
4. Illustrate your ans with neat sketches wherever necessary.
5. Mobile phones, pager and other electronic communication devices are not permissible in
exam hall.
6. Write the answers in sequential order.


Q.1 a) Attempt any 6 of the subsequent [Marks 12]
a) Draw the symbols of LED and UJT.
b) describe NTC of thermistor.
c) describe line and load regulation.
d) List the various kinds of triggering devices along with their symbols. (Any 2 devices)
e) State Barkhauson's criteria to find the sustain oscillation.
f) Draw the symbol of D-flip-flop. Write the truth table for the identical.
g) Compare L and C kind filters used in rectifiers.
h) Draw the circuit diagram of an inverting amplifier using IC741. OPAMP.


b) Attempt any 2 of the subsequent [Marks 8]
a) discuss the working of photo diode. Draw its characteristics.
b) Draw the equivalent circuit of UJT and discuss its I-V characteristics.
c) Draw the block diagram of series voltage regulated power supply and discuss its working.


Q.2 Attempt any 4 of the subsequent [Marks 16]
a) Draw the circuit diagram of zener diode as a voltage regulator in line regulation and discuss
its operation.
b) discuss the working principle of Bridge rectifier with neat circuit diagram and necessary
waveform.
c) Draw the circuit of +9V and -9V regulated D.C. output power supply using 78XX, 79XX series of
ICs.
d) Draw the complete circuit diagram of regulated power supply. (Circuit includes FWR, filter and
regulator) and discuss the working of every block in short.
e) Compare ripple factor, rectification efficiency for half wave rectifier and full wave rectifier.


Q.3 Attempt any 4 of the subsequent [Marks 16]
a) Draw the circuit of two stage RC coupled CE amplifier. discuss its frequency response with neat
diagram.
b) State conduction angle, operating point, efficiency and 1 application for class A and class B
power amplifier.
c) Draw the circuit diagram of Hartley oscillator and discuss its working principle.
d) Draw the circuit diagram of transistor in CE configuration. Draw its input and output
characteristics.
e) define the working principle of RC phase-shift oscillator with circuit diagram.
f) Draw the circuit diagram of colpitts oscillator. State the formula for its output frequency.


Q.4 Attempt any 4 of the subsequent [Marks 16]
a) define the working principle of optocoupler.
b) describe any 4 specifications of operational amplifier.
c) define how up-amp is used as an adder.
d) discuss the non-inverting mode of op-amp with neat circuit diagram. Write its input and output
relation.
e) How op-amop is used in instrumentation amplifier? Draw necessary circuit diagram.
f) Compare Bipolar junction transistor and field effect transistor for 4 points.



Q.5 Attempt any 4 of the subsequent [Marks 16]
a) What is BCD number system. Write BCD of no. (23).
b) discuss the working of JK flip flop with the help of diagram and write its truth table.
c) discuss the working of 4-bit ring counter using flip-flop.
d) Implement AND, OR and NOT gates by using NAND gates only.
e) Convert (6AC)₁₆ into decimal and binary number system.
f) Draw the block diagram of 1:4 Demultiplexer and discuss its working.


Q.6 Attempt any 4 of the subsequent [Marks 16]
a) discuss the VI characteristics of P-N junction diode with neat circuit diagram.
b) Draw the circuit diagram of astable multivibrator using IC 555 and discuss its working.
c) define successive approximation method of ADC with neat diagram.
d) With improper block diagram define the working of sequential timer.
e) discuss R-2R ladder network method of DAC.
f) Which configuration of transistor is used foe very high frequency application why?

Earning:   Approval pending.