University Model Examination - Digital Electronics - 4BPH6C2


              Part - A               

1.Convert the decimal number 65.6 into hexadecimal.
2.State distributive laws of Boolean algebra.
3.Simplify the Boolean expression A(A+B+AB).
4.What is the difference between Karnaugh map and truth table.
5.What is meant by flip-flop?
6.How many flip-flops are required to construct a MOD-9 counter.
7.Write the equivalent analog voltage of (11011001)2  if the full scale voltage is 5 V.
8.Write note on resolution of an ADC.
9.What is the advantage of a PROM over ROM?
10.What is a magnetic bubble memory?

Part - B

11.(a) Describe the function of an AND gate with its truth table.
(OR)
     (b)State and prove De Morgan's Theorem 
12.(a) Explain the working of Half Adder.
(OR)
     (b) Construct and simplify K-map for the expression f(A,B,C,D) = ∑(0,1,4,6,7,8,9,10,11,15).
13.(a) Describe the action of an RS flip-flop with neat circuit diagram and truth table.
(OR)
     (b) Explain the working of Johnson counter.
14.(a) How does a simultaneous ADC operates?
(OR)
     (b) Explain the counter type ADC.
15.(a) Explain the function of a MOS Static RAM cell.
(OR)
     (b) Discuss the construction details of  magnetic disc memories.

Part - C

16. Explain how NOR gate can be used a universal building block.
17. Explain the working of an 8421 BCD Binary adder.
18. With a neat diagram, explain the action of a 4-bit shift register. 
19. Describe the working of a weighted registor type D/A converter.
20.What is a PROM? Explain how a PROM can be programmed with neat diagrams.