(a) Write the truth tables of (i) AND gate and (ii) NOT gate.
(b) Show how an OR gate may be obtained with the combination of NAND gates.
(a) AND gate
A logic gate which performs the Boolean function Y = A.B
A | B | AB |
0 | 0 | 0 |
0 | 1 | 0 |
1 | 0 | 0 |
1 | 1 | 1 |
(ii) NOT gate
A logic which performs the Boolean function
A | |
0 | 1 |
1 | 0 |
(b) NAND gate
A logic gate which performs the Boolean function
NAND gate is a universal gate
A | B | |
0 | 0 | 1 |
0 | 1 | 1 |
1 | 0 | 1 |
1 | 1 | 0 |
By using NAND gate we can make any gate.
For OR logic
OR logic is C = A + B
NAND logic C =
By applying Demorgan's thereom
OR gate
By using 3 NAND gate we can make an OR gate.