Understanding PMOS and NMOS logic families PMOS and NMOS logic families primarily:

Introduction / Context:
Before complementary MOS (CMOS) dominated, digital ICs were often implemented using only one transistor polarity: PMOS or NMOS. Knowing this historical and architectural distinction helps in understanding device behavior, speed, and power characteristics compared to CMOS.

Given Data / Assumptions:

• PMOS uses only p-channel MOSFETs in logic gates.
• NMOS uses only n-channel MOSFETs in logic gates.
• CMOS uses both p- and n-channel devices in complementary pairs.

Concept / Approach:
Single-polarity MOS logic (PMOS/NMOS) simplifies fabrication but suffers from static power dissipation (through resistive or depletion loads) and limited noise margins compared to CMOS. CMOS leverages both polarities to reduce static power and improve switching characteristics. The 74HC series refers to high-speed CMOS, not PMOS/NMOS-only logic.

Step-by-Step Solution:

Verification / Alternative check:
Classic NMOS microprocessors (e.g., early 6502 variants) and PMOS logic families illustrate single-polarity construction.

Why Other Options Are Wrong:

• B: 74HC is CMOS, not PMOS/NMOS-only.
• C: “positive/negative” and differential-supply claims are unrelated to PMOS/NMOS definitions.
• D: Not applicable since A is correct.

Common Pitfalls:
Confusing PMOS/NMOS with CMOS; forgetting that CMOS combines both channel types.

Final Answer:
represent MOSFET devices utilizing either P-channel or N-channel devices exclusively within a given gate