Question

The combination of ‘NAND’ gates shown here under (figure) are equivalent to

• A. An OR gate and an AND gate respectively
• B. An AND gate and a NOT gate respectively
• C. An AND gate and an OR gate respectively
• D. An OR gate and a NOT gate respectively

Answer 1

The correct option is A An OR gate and an AND gate respectively

For 1st combination
$C=\overline{\overline{A.A}\overline{B.B}}$
A.A. = A & B.B. = B
$C=\overline{\overline{A}.\overline{B}}$
$C=\overline{\overline{A}}\overline{\overline{B}}$
C = A + B
It is an OR gate
For $2^{nd}$ combination
$C=\overline{\overline{A.B}.\overline{A.B}}$
$C=\overline{\overline{A.B}}.\overline{\overline{A.B}}$
C = AB + AB
C = AB
Its an AND gate