Question

1) You are given the circuit as shown in figure. Show thatcircuit acts as OR gate.


2)You are given the circuit as shown in figure. Show that
circuit acts as AND gate.

Answer 1

1) Given, input for the circuit, $AandB$ Output for the circuit, Y
In the given circuit the left one is $NOR$ gate and the right one is$NOT$ gate.


Output for the NOR gate=$\overline{A+B}$

$\overline{A+B}$is input for the $NOT$ gate,

Output for the $NOT$ gate =$\overline{\overline{A+B}}$

This will be output for the circuit

$Y=\overline{A+B}$

$Y=A+B$

$\begin{array}{cc}INPUTS& OUTPUT\\ AB& Y\\ 00& 0\\ 01& 1\\ 10& 1\\ 11& 1\end{array}$

Therefore, the circuit act as $OR$ gate.

Final answer: the circuit act as $OR$ gate.


2) Given, input for the circuit, $AandB$
Output for the circuit, $Y$
In the given circuit the left two is $NOT$ gate and the right one is$NOR$ gate.



Output for the $NOT$ gate=$\overline{A}$ and $\overline{B}$ , $\overline{A}$ and 𝐵 $\overline{B}$ are inputs for the $NOR$ gate, Output for the NOR gate =$\overline{\overline{A}+\overline{B}}$

This will be output for the circuit

$Y=\overline{\overline{A}+\overline{B}}$

$Y=\overline{\overline{A}}.\overline{\overline{B}}$

$\begin{array}{cc}INPUTS& OUTPUT\\ AB& Y\\ 00& 0\\ 01& 0\\ 10& 0\\ 11& 1\end{array}$

Therefore, the circuit acts as $AND$ gate.

Final answer: the circuit acts as $AND$ gate