Q 12-14-040JEE MainJEE Main 2026 (5 Apr, Shift 1)Medium
For the given logic circuit, which of the following inputs combination will make both LED-1 and LED-2 to glow?
Answer: (C) $A = 1, B = 0, C = 1$
LED-1 is driven by the OR gate: it glows when $A + B = 1$.
The second gate is an AND of $(A + B)$ and $C$; the last gate is an AND of that with $A$. So LED-2 glows when $A(A + B)C = AC = 1$.
Both glow when $A = 1$ and $C = 1$ (then $A + B = 1$ automatically). Only $A = 1, B = 0, C = 1$ fits.
Solution by Sreeraj P, M.Sc Physics