Explanation

(a) If we connect the output $Y'$ of AND gate to the input of a NOT gate as shown in figure, the gate so obtained is called NAND gate. The truth table of NAND gate can be obtained by logically using the truth table of AND and NOT gates as shown in figure.
[image:14_image220.jpeg]
Truth Table
[table] $\mathbf{A}$ | $\mathbf{B}$ | $\mathbf{Y}$ ; $0$ $1$ $0$ $1$ | $0$ $0$ $1$ $1$ | $1$ $1$ $1$ $0$ [/table]