Page 68 - computer science (868) class 11
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C. Answer the following questions:
1. Draw the truth table of (i) conditional (ii) biconditional
Ans. a b a → b a ↔ b
0 0 1 1
0 1 1 0
1 0 0 0
1 1 1 1
2. Draw the logic circuit diagram of the following Boolean expressions using AND, and OR gates. Assume complement is available
as input.
(i) (B'+D).(A'+D').(B+C'+D') (ii) (B'.C'+A.C)'
Ans. (i)
B' (B'+D)
D
A' (A'+D') (B'+D).(A'+D').(B+C'+D')
D'
B
C' (B+C'+D')
D'
(ii)
B' B'.C'
C'
(B'.C'+A.C)'
A
C A.C
3. Draw a logic circuit diagram to represent AND, OR and NOT gates using NOR gate only.
Ans. (i) NOT gate using NOR gate
A (A+A)' A' (A+A)'
A =A'
(ii) OR gate using NOR gate
A (A+B)' (A+B) = ((A+B)')'
B = (A + B)
(iii) AND gate using NOR gate
A A'
A (A'+B)')'
A.B
= A" . B"
= A . B
B B'
B
6666 Touchpad Computer Science-XI

