Q 12-14-210JEE MainJEE Main 2025 (3 Apr, Shift 1)Easy
Choose the correct logic circuit for the given truth table having inputs A and B.
$$\begin{array}{|c|c|c|}\hline A & B & Y \\ \hline 0 & 0 & 0 \\ \hline 0 & 1 & 0 \\ \hline 1 & 0 & 1 \\ \hline 1 & 1 & 1 \\ \hline \end{array}$$
The four circuits are shown in the figure.
Answer: (B) Circuit (2)
From the table, $Y = 1$ exactly when $A = 1$, so $Y = A$.
Work out each circuit (the OR gate always gives $A + B$):
- (1) $Y = (A + B)\cdot B = B$ ✘
- (2) $Y = (A + B)\cdot A = A$ ✔ (absorption law)
- (3) $Y = \overline{(A + B)}\cdot A = 0$ always ✘
- (4) $Y = (A + B)\cdot\overline A = \overline A B$ ✘
Circuit (2) matches the table.
Solution by Sreeraj P, M.Sc Physics