Difficulty: Easy
Correct Answer: Incorrect
Explanation:
Introduction / Context:In adder schematics and block diagrams, the symbol Σ commonly labels the sum function/output, not the carry. Carry signals are typically labeled Cin and Cout (or Cn and Cn+1) explicitly.
Given Data / Assumptions:
Concept / Approach:A one-bit full adder implements Sum = A xor B xor Cin and Cout = majority(A, B, Cin). Documentation and textbooks identify Σ with the Sum output; Cout is a distinct signal and is not denoted by Σ.
Step-by-Step Solution:
Check conventional labeling: Σ → sum output S.Carry uses C-labels (Cin/Cout) or explicit “carry.”Therefore, the statement is incorrect.Verification / Alternative check:Datasheets (e.g., 74xx/HC283 adders) show S outputs and a separate Cout pin; Σ is associated with summation, not carry.
Why Other Options Are Wrong:
Correct / parallel-only / ambiguous: All mischaracterize standard symbols.Insufficient context: The notation is broadly consistent.Common Pitfalls:Misreading Σ as “anything related to addition,” including carry. It designates the sum.
Final Answer:Incorrect
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