The correct truth table for the given input data of the following logic gate is : [figure]
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Answer
(1) [figure]
Solution
First gate: AND followed by NOT NAND: output = A B
Second gate: OR: output = C + D
Third gate: AND followed by NOT NAND of the two outputs:
Y = A B (C + D)
Y = A B + C + D (De Morgan's theorem)
Row 1: A = 1, B = 1 A B = 1 Y = 1
Row 2: A B = 0, C + D = 1 Y = 0
Row 3: A B = 0, C + D = 1 Y = 0
Row 4: A B = 1 Y = 1
Y column: 1, 0, 0, 1, which matches the first table.
Answer: (1)