UGC NET Questions (Paper – 1)

The base of a positional number system is technically called its radix. Radix denotes how many distinct symbols are used, such as 2 for binary or 10 for decimal. All positional weights are powers of the radix, which is why this term is central in number system discussions. Therefore, radix is the correct technical name for the base.

Option A:
Option A is correct because radix directly refers to the base of a number system and determines the positional weights. When we say base 10 or base 2, we are specifying the radix. In many mathematical texts, the words base and radix are used interchangeably, confirming that radix is the appropriate term.

Option B:
Option B, exponent, refers to the power to which a base is raised in an expression like 2^3. It describes the position in a power expression, not the base itself. Hence, exponent cannot be used as a synonym for base of the number system.

Option C:
Option C, mantissa, is a term used in logarithms and floating-point representation to denote the significant digits. It does not describe how many symbols a number system uses or what its base is. Therefore, mantissa is not an appropriate replacement for the term base.

Option D:
Option D, modulus, generally refers to the divisor in modular arithmetic or the absolute value of a number. While related to number theory, modulus does not mean the same thing as base or radix in positional number systems. So it is not the correct choice here.