Question

A two-input NAND gate is followed by a single-input NOR gate. This logic circuit will function as :

• A. an opposite to AND gate
• B. an OR gate
• C. a NOT gate
• D. a NOR gate

Answer 1

The correct option is B an OR gate

The equivalent logic of the whole system can be written as $\overline{\left(\overline{\text{A}}.\overline{\text{B}}\right)}$

$\text{A B}\left(\overline{\text{A}}\text{.}\overline{\text{B}}\right)$

$\text{1 1 0}$

$\text{0 0 1}$

$\text{1 0 1}$

$\text{0 1 1}$

Clearly, this works like a OR-gate.

The option (B) is correct.