In digital electronics, an OR gate can be conceptualized using simple switch analogies—how should the switches be connected to reflect the OR function (so the output path conducts if any input is asserted)?

Introduction / Context:
Digital logic gates are often explained with intuitive switch analogies. An OR gate outputs logic high when any input is high. Mapping this behavior to basic on/off switches helps students visualize conduction paths and understand why OR differs from AND at a physical or conceptual level.

Given Data / Assumptions:

• Positive logic is assumed: closed switch = logic 1 path enabled.
• Goal: replicate OR behavior using idealized switches.
• Output is considered connected to a source through a network of input-controlled switches.

Concept / Approach:

If the output must conduct when any input is asserted, then each input should provide an independent conducting path. The natural way to realize independent paths is to place the input-controlled elements in parallel. In parallel, closure of any one branch establishes continuity from source to output, mirroring the inclusive OR truth table.

Step-by-Step Solution:

Verification / Alternative check:

Truth-table comparison shows that parallel branches reproduce the OR column exactly: only when all branches are open (all inputs low) does the output fail to conduct.

Why Other Options Are Wrong:

Series switches implement AND (all must close). 'MOS transistors connected in series' describes an AND-like pull-down in CMOS, not the OR analogy asked. 'All of the above' cannot be correct because series contradicts the OR requirement.

Common Pitfalls:

Confusing CMOS pull-up/pull-down topology (mixed series/parallel) with the simple switch analogy, and forgetting that OR requires alternative, not cumulative, paths.

Final Answer:

switches connected in parallel