# Computer Based Construction Question Paper

B.E. DEGREE EXAMINATION

## ELECTRONICS AND MICROPROCESSOR

Time : Three hours                                                                        Maximum : 100 marks

PART A — (10 ´ 2 = 20 marks)

1. Explain with reference to energy band theory the difference between conductors, isolators and semiconductors.

2. What are the three configuration of a transistor amplifier?

3. Draw a neat diagram of a single SCR based half wave rectifier circuit and draw the voltage characteristics.

4. Explain a biasing circuit for BJT.

5. Write the truth table for AND, OR, NOR and XOR gates.

6. Distinguish the terms mono–stable and astable multi vibrators.

7. Write a program using INTEL 8085 instructions, to add two 8–bit numbers and store the result in the memory.

8. Distinguish the instructions DAA and DADH of Intel 8085.

9. Explain the range of,  and  control lines while interfacing a memory to an 8085 processor.

10. What is meant by a tri state buffer?  Where do we use the buffer?

PART B — (5 ´ 16 = 80 marks)

11. (i)      Illustrate with a neat sketch the architecture of Intel 8085 processor.

(10)

(ii)     Distinguish the features of Z80 processor over the Intel 8085 processor.

(6)

12. (a)     (i)      Illustrate with a neat sketch the functioning of a Full–wave bridge rectifier.                             (10)

(ii)    Explain with a neat sketch the use of TRIAC for AC voltage control.

(6)

Or

(b)     (i)      Illustrate with a neat sketch how power amplification will be obtained through electronic circuits.                             (8)

(ii)    Illustrate with a neat sketch the functioning of a voltage regulator.

(8)

13. (a)     (i)      What are flip–flops?  Realise a 3–bit counter using Flip–Flops.  (8)

(ii)    Realise a full adder and a decoder circuit using Logic gates.       (8)

Or

(b)     (i)      Explain the use of operational amplifiers with the help two of its application circuits.                                             (8)

(ii)    Realise a multiplexer and a demultiplexer using logic gates.      (8)

14. (a)     Explain the processes involved in fabrication of an IC.                        (16)

Or

(b)     (i)      Compare the V–I characteristics of a Zener Diode to that of a Tunnel diode.                              (8)

(ii)    Explain one application circuit for each of the following namely, Zener diode, LED and thermistor.                       (8)

15. (a)     Illustrate with a neat sketch the interface of a matrix keyboard to
Intel 8085 processor.  Also write a program to enter key data into memory.                                       (16)

Or

(b)     Write short notes on the following :

(i)      Serial communication with the microprocessors.                           (8)

(ii)    Application of microprocessors.                                                        (8)

Anna University Civil Engineering and Computer Based Construction Question Paper

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