Consider wiring practices for TTL outputs: if you tie the outputs of several standard TTL totem-pole gates directly together, does this safely increase available fan-out? Judge the statement.

Introduction / Context:
Digital outputs are not meant to be tied together arbitrarily. Standard TTL gates use totem-pole outputs that actively drive both HIGH and LOW. Shorting multiple drivers can cause destructive contention currents and undefined logic levels.

Given Data / Assumptions:

• Devices: standard TTL with push–pull outputs.
• Practice in question: tying outputs together to “increase fan-out.”
• Fan-out properly refers to one output driving multiple inputs, not multiple outputs tied together.

Concept / Approach:
Fan-out is achieved by ensuring one driver meets the total input current of all loads. You do not parallel outputs unless they are specifically designed for current sharing (rare in logic ICs). For wired-OR functionality, open-collector (TTL) or open-drain (CMOS) with a pull-up is used; totem-pole outputs must not be tied.

Step-by-Step Solution:
Identify output type → totem-pole drives both states aggressively.Consider tying two drivers → contention whenever they disagree.Result → potential damage, excessive current, undefined logic; does not “increase fan-out.”

Verification / Alternative check:
Datasheets warn against connecting outputs together except with open-collector/open-drain architectures and proper pull-ups or bus transceivers using tri-state control.

Why Other Options Are Wrong:
“Correct” is unsafe. “Valid only for open-collector…” is a different topology, not “standard TTL outputs tied directly.” Tri-state also requires bus control to ensure only one active driver at a time.

Common Pitfalls:
Confusing “one output to many inputs” (fan-out) with “many outputs to one node” (bus contention risk).

Final Answer:
Incorrect