Definition check: In digital logic, a “variable” denotes a symbol representing a logical quantity that can assume the value 1 or 0. Evaluate this statement.

Difficulty: Easy

Correct Answer: Correct

Explanation:


Introduction / Context:
Precise terminology is essential in Boolean algebra and digital systems. A variable is a placeholder for a logical value that can change according to inputs, states, or time. Understanding this definition underpins work with truth tables, K-maps, and HDL descriptions.


Given Data / Assumptions:

  • The logical domain is binary: {0, 1}.
  • Variables may be complemented (~A) or uncomplemented (A).
  • Expressions are composed using OR (+), AND (*), and NOT (~).


Concept / Approach:
A Boolean variable represents a logical quantity that can be either 0 (false/LOW) or 1 (true/HIGH). This is distinct from multi-valued logic systems (e.g., ternary or 4-state simulation), which extend beyond basic Boolean algebra typically taught in introductory courses.


Step-by-Step Solution:

Interpret “variable” as a symbol like A, B, or C.Allowable values in Boolean algebra: 0 or 1.Use in expressions and truth tables assumes binary evaluation.Therefore, the statement correctly defines a Boolean variable.


Verification / Alternative check:
Truth tables treat each variable as taking 0 or 1, enumerating 2^n combinations for n variables. HDL signals in simple combinational contexts also behave as binary variables under idealized models.


Why Other Options Are Wrong:

  • Incorrect: Conflicts with the standard definition in Boolean logic.
  • Ambiguous as stated: The statement specifies values clearly (0 or 1).
  • Cannot be determined: No further information is needed; it is definitional.


Common Pitfalls:
Conflating Boolean variables with arithmetic variables that can take many integer values. In logic, the domain is strictly binary unless otherwise noted (e.g., X/Z states in simulation models).


Final Answer:
Correct

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