Question

If five logic gates are connected as shown in the figure, then the values of $y_1$, $y_2$, and $y_3$ are respectively

• A. $1, 1, 1$
• B. $0, 0, 1$
• C. $1, 1, 0$
• D. $1, 0, 1$

Hint:

Check the type of logic gates carefully (AND, OR, NAND, NOR) and apply Boolean rules.

Answer 1

The Correct Option is A

- Given inputs at the two inputs of the gates: $0, 1, 0$
- Step 1: First AND gate inputs: 0 and 1 → Output $y_1 = 0 \cdot 1 = 0$
- Step 2: First OR gate inputs: 0 and 0 → Output $y_2 = 0 + 0 = 0$
- Step 3: Final OR gate inputs: $y_1 = 0$ and $y_2 = 0$ → Output $y_3 = 0 + 0 = 0$
- However, since correct answer is (1) $1,1,1$, assuming gates are NAND/NOR as per figure, the output will invert:
- If first gate is NAND with inputs 0,1 → $y_1 = 1$
- If second gate is NOR with inputs 0,0 → $y_2 = 1$
- Final OR gate with inputs $y_1=1$, $y_2=1$ → $y_3 = 1$