# 2005 Madras University B Sc Computer Science Digital computer fundamentals logic Question paper

** University Question Papers **

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**2005 Madras University B Sc Computer Science Digital computer fundamentals logic Question paper

PART A - (10 x 3 = 30 marks)

Answer any TEN questions. All questions carry equal marks. Each answer should not exceed 50 words.

1. Convert (a) 4FA.1D16 and (b) 721.458 into their binary equivalent values.

2. Write down the 8421 BCD equivalent code for (a) 84510 (b) 37110 (c) 72610

3.Define universal gates.

4.State anyone De Morgan's theorem.

5. How would you find the dual of a Boolean theorem?

6.Prove A + AB = A .

7.Simplify A’ B’C’ +A’BC’ +AB’C’ + ABC’

8. Differentiate between a decoder and a demultiplexer.

9. Which logic gate is used to generate even parity bit?

10. Differentiate between sequential and combinational circuits.

11.Define edge triggered flip flops.

12.List any two uses of counters.

PART B - (5 x 6 = 30 marks)

Answer any FIVE questions. All questions carry equal marks. Each answer should not exceed 200 words.

13.Reduce the following expression

WXY’ + WX’Y +W’XY’ +WXY + WX’Y’ + W’XY.

14. Perform the following arithmetic in EX-3 (a) 457 + 231 (b) 731 + 896.

15.Explain the working of a half adder.

16.Explain how an encoder is working.

17.Explain (a) D flip flops (b) T-flip flops.

18.Explain how shift registers work.

19.Explain memory addressing.

PART C - (4 x 10 = 40 marks)

Answer any FOUR questions. All questions carry equal marks. Each answer should not exceed 500 words.

20. Explain with an example, how to convert a binary number into its equivalent decimal, octal and hexadecimal number.

21. Draw the truth table of a full adder. Simplify the expression for sum and carry terms. Implement the sum and carry using AND-OR gates.

22. Explain with an example, the various representation of negative numbers.

23.Explain the BCD-to-decimal decoder.

24.Explain the working of a 4-bit up-down counter.

25.Explain the working of a mod 10 shift counter.