Question

In the logic circuit diagram, when all the four inputs, A, B, C, D are 'one' the outputs \(Y_1\), \(Y_2\), \(Y_3\) are respectively (1, 1, 0). When the inputs A and C are changed to zero and B and D are still 'one', then the outputs \(Y_1\), \(Y_2\), \(Y_3\) are respectively change to

• A. \(1,1,1\)
• B. \(1,0,0\)
• C. \(0,1,0\)
• D. \(0,0,1\)

Hint:

Y1 = NOT(NOR(A, B)) = A OR B, Y2 = C AND D, Y3 = NOR(Y1, Y2).

Answer 1

The Correct Option is B

Step 1: Gate by gate
NOR then NOT on A and B is an OR gate. C and D go through AND. The last gate is NOR.

Step 2: Truth values
With $A = 0, B = 1$: OR gives 1. With $C = 0, D = 1$: AND gives 0.

Step 3: Last gate
NOR of $(1, 0)$ is 0. So $(Y_1, Y_2, Y_3) = (1, 0, 0)$, option (B).

Final Answer:
Option (B). \[ \boxed{(1, 0, 0)} \]