JEE Physics 2023 Question with Solution

Given: A NAND gate with input waveforms $A$ and $B$.

Find: The correct output waveform.

A NAND gate gives the negation of the AND output.

So the output is $1$ for all input combinations except when both inputs are $1$.

From the truth table:

• When $A = 0$ and $B = 0$, $Y = 1$
• When $A = 0$ and $B = 1$, $Y = 1$
• When $A = 1$ and $B = 0$, $Y = 1$
• When $A = 1$ and $B = 1$, $Y = 0$

Now compare the given input waveforms interval by interval, first finding $A \cdot B$, and then taking its complement to obtain $Y$.

From the given inputs and truth table, the output waveform matches Option (2).

Therefore, the correct option is B.