Question

The following figure shows a logic gate circuit with two inputs $A$ and $B$ and the output $C$. The voltage waveforms of $A,B\text{and}C$ are shown below.


The logic circuit gate is :

• A. $\text{AND gate}$
• B. $\text{NAND gate}$
• C. $\text{NOR gate}$
• D. $\text{OR gate}$

Answer 1

The correct option is A $\text{AND gate}$

From the figure,

$C=1$ when $A=1\text{and}B=1$

We can also observe that for all other combinations, output $C$ has low value $\left(0\right)$,i.e,

$A=0,B=1,C=0A=0,B=0,C=0$

Thus, the logic circuit is an $\text{AND}$ gate.

Hence, option $\left(A\right)$ is correct

Why this question ? Tip : In the problems with input and output represented as waveform, assign the peak value or high value as $1$ and the low value as $0$.