Digital codes and voltage levels: “The decimal code system uses ten distinct voltage levels.” Judge this statement considering common coding schemes such as BCD.

Introduction / Context:
Digital systems often represent decimal digits, but the physical signaling is still binary. Binary-coded decimal (BCD), seven-segment encoding, and ASCII all use combinations of binary lines rather than ten DC voltage levels per wire.

Given Data / Assumptions:

• “Decimal code system” refers to digital representation of digits 0–9.
• Physical wires in typical logic use LOW/HIGH only.
• We evaluate whether ten voltage levels are actually used.

Concept / Approach:
BCD uses 4 binary bits to encode 0–9. Each bit is one of two voltage levels. A multi-wire combination creates ten codes, not ten analog levels on one wire. Other codes (ASCII) similarly use multiple binary lines or serial binary streams to represent decimal symbols.

Step-by-Step Solution:

Verification / Alternative check:
Datasheets for BCD counters/decoders show binary outputs and two-level inputs; displays are driven via decoders, not tramite ten-level voltages.

Why Other Options Are Wrong:
Correct: Conflicts with binary signaling practice.

True only for legacy TTL / analog computers: TTL is binary; analog computers do not use “decimal code levels” as defined here.

Common Pitfalls:
Equating ten symbols with ten voltage levels. Confusing code cardinality with signaling levels.

Final Answer:
Incorrect