Weighted vs non-weighted code – UGC NET Question

In a weighted code, each digit position carries a predetermined weight, usually a power of the radix. Positional number systems like decimal and binary are weighted because the value of a digit depends on both its magnitude and its position. Therefore, such systems are described as weighted codes.

Option A:
Option A correctly identifies that fixed positional weights, such as 1, 10, 100 in decimal or 1, 2, 4, 8 in binary, define a weighted code. The overall value is found by summing the products of digits and their weights, which is characteristic of these systems.

Option B:
Option B, non-weighted, refers to codes like Gray code or some error-detecting codes where positions do not correspond to simple powers of a base. These systems do not use fixed positional weights, so this term is not appropriate here.

Option C:
Option C, redundant, describes codes that use more bit patterns than strictly necessary to represent a set of values. While some weighted codes can be redundant, redundancy is not the defining feature in this context.

Option D:
Option D, residue, refers to codes representing numbers using modular arithmetic, such as residue number systems. These systems behave differently from standard positional weighted codes.