For a standard bistable flip-flop with complementary outputs, what is the relationship between Q and Q' (Q bar) under normal operation?

Introduction / Context:
Flip-flops store one bit of state and present two outputs: Q and Q' (also written as Q-bar). Understanding their relationship is essential when designing sequential circuits and avoiding illegal feedback paths.

Given Data / Assumptions:

• Standard flip-flop topology with Q and Q' provided.
• No metastability or invalid input conditions are considered here.
• Outputs are measured in the stable state after inputs/clock settle.

Concept / Approach:
By design, Q' is the logical complement of Q. When Q = 1, Q' = 0; when Q = 0, Q' = 1. This complementary behavior is fundamental to cross-coupled latch structures and edge-triggered flip-flops.

Step-by-Step Solution:

Verification / Alternative check:
Cross-coupled inverters/NANDs/NORs enforce mutual inversion: feeding back ensures only one of the two nodes is high at a time in a stable state.

Why Other Options Are Wrong:

• the same: violates the cross-coupled structure; both high or both low is unstable/invalid.
• independent of each other: incorrect; they are tightly coupled.
• same as inputs: outputs depend on internal state and clocking, not direct combinational equality.
• None of the above: incorrect because 'complementary' is correct.

Common Pitfalls:
Confusing complementary with 'complimentary' (spelling) and overlooking transient hazards during switching.

Final Answer:
complementary