Difficulty: Easy
Correct Answer: Incorrect (A < B = 1, A = B = 0, A > B = 0)
Explanation:
Introduction / Context:
The 7485 magnitude comparator outputs three mutually exclusive flags: A<B, A=B, and A>B. Only one of these should be asserted for any well-defined comparison. This problem tests your ability to evaluate a specific input pair and verify consistent outputs.
Given Data / Assumptions:
Concept / Approach:
Compare A and B numerically as unsigned binary. Since 6 is less than 10, the correct flags are A<B = 1, A=B = 0, A>B = 0. The claim that both A<B and A>B are 1 simultaneously violates mutual exclusivity and is logically inconsistent.
Step-by-Step Solution:
Convert to decimal or compare bitwise from MSB: A(0110) vs B(1010).MSB comparison: A3=0, B3=1 → immediately implies A<B.Therefore set outputs: A<B = 1, A=B = 0, A>B = 0.Compare with claim: claim has A>B = 1 as well → inconsistent → false.
Verification / Alternative check:
7485 truth tables show that when the highest unequal bit indicates A<B, the lower bits do not change the outcome; only one relation output is asserted (taking into account cascade inputs which are assumed inactive here).
Why Other Options Are Wrong:
“Correct as stated” would require simultaneous greater and less, which cannot happen. Considering signed interpretation or ignoring the MSB does not apply; the device compares given bit patterns as provided.
Common Pitfalls:
Forgetting the mutual exclusivity; misreading bit order; letting lower bits override a decision already made by a higher bit.
Final Answer:
Incorrect (A < B = 1, A = B = 0, A > B = 0)
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