1. Reg. No. :
9
Question Paper Code: E3137
22
B.E./B.Tech. DEGREE EXAMINATION, APRIL/MAY 2010
Fourth Semester
Mechanical Engineering
ME2255 — ELECTRONICS AND MICRO-PROCESSORS
(Common to Automobile Engineering, Production Engineering)
(Regulation 2008)
Time: Three hours Maximum: 100 Marks
Answer ALL Questions
PART A — (10 × 2 = 20 Marks)
1.
2.
9
Draw the circuit of zener voltage regulator.
A half wave rectifier having a resistance load of 1 k Ω rectifies an alternating
voltage of 325 V peak value and the diode has a forward resistance of 100 Ω .
22
Calculate its dc power output.
3. What is early effect in BJTs?
4. Define voltage safety factor of thyristor.
5. Using Boolean laws, prove that X ⋅ Y + Y = X + Y .
6. Convert the following circuit into its equivalent NAND circuit :
9
7. Specify the output at port 1 if the following ALP is executed :
22
MV1 B, 88 H
MOV A, B
MOV C, A
MV1 D, 73 H
Out port 1
HLT

2. 8. List the interrupts and their call locations.
9
9. Define interfacing devices.
10. What is transceiver?
PART B — (5 × 16 = 80 Marks)
22
11. (a) Draw and explain the formation of a PN junction and explain the
working of the diode under forward and reverse bias conditions.
Or
(b) Is it possible to replace a zener diode with an ordinary rectifier diode? If
no, explain the desired characteristics of zener diode.
12. (a) With neat circuit diagrams, explain the methods of transistor biasing.
Or
(b) Write in detail about the operation of JFET under various biasing
conditions.
13. (a) 9
Implement the full adder circuit from its truth table.
Or
22
(b) Design a 4 bit binary parallel counter. Support your answer with circuit
diagram and truth table.
14. (a) What are the addressing modes supported in 8085 cpu? Explain each of
them with minimum of 2 sample instructions.
Or
(b) Explain the architecture of 8085 with the required diagrams. Also write
the salient features of the same.
15. (a) How to control the speed of stepper motor with 8085 cpu and its
interface? Draw a neat interface diagram and explain its operation.
9
Or
(b) Design a traffic light control system using 8085 cpu. Write its sequence of
operation with neat block diagram of the system. Support your answer
with the software flowchart.
22
——————
2 E 3137