Signed number representations in digital systems: In sign–magnitude representation, a signed binary number reserves one dedicated sign bit, while the remaining bits represent the magnitude. Evaluate this statement in the context of common signed formats used in digital electronics.

Introduction / Context:
Digital electronics and computer arithmetic use several ways to encode negative integers. The two most frequently discussed are sign–magnitude and two's complement. The statement says that a “signed binary number” has one sign bit and the rest of the bits hold the magnitude. This is strictly true for the sign–magnitude format, and the question asks you to evaluate it with that context in mind.

Given Data / Assumptions:

• We are talking about signed integer encodings used in hardware.
• In sign–magnitude, the most significant bit (MSB) is the sign indicator.
• In two's complement, the MSB also indicates negativity, but the remaining bits do not simply hold the magnitude; the code is weighted.

Concept / Approach:
In sign–magnitude, the layout is: sign bit (0 for positive, 1 for negative) + magnitude field (binary of the absolute value). In two's complement, negativity is encoded by inverting and adding 1, which changes the numeric weighting of all bits. Therefore, the literal description “one sign bit + magnitude bits” is accurate for sign–magnitude, not for two's complement.

Step-by-Step Solution:

Verification / Alternative check:
Examples: With 8 bits, +5 is 0000 0101; −5 in sign–magnitude is 1000 0101. The magnitude field is unchanged; only the sign bit flips.

Why Other Options Are Wrong:
“Incorrect” ignores the validity for sign–magnitude. “Applies only to octal numbers” is irrelevant. “Insufficient information” is unnecessary because the stem explicitly frames sign–magnitude.

Common Pitfalls:
Confusing sign–magnitude with two's complement, where bit patterns are not a simple sign + magnitude.

Final Answer:
Correct