Question

The most widely used code that represents each character as a unique 8-bit code is:

• A. \( \text{ASCII} \)
• B. \( \text{UNICODE} \)
• C. \( \text{BCD} \)
• D. \( \text{All of the above} \)

Hint:

ASCII was the foundational character encoding standard for English characters, commonly extended to 8 bits. Unicode (especially UTF-8) is the modern standard for international characters but uses variable-length encoding. BCD is specifically for encoding decimal digits. For questions specifying "8-bit code" for characters, Extended ASCII is often the intended answer in historical or introductory contexts.

Answer 1

The Correct Option is A

Step 1: Analyze the requirements: The code must be widely used and represent characters using a unique 8-bit code. Step 2: Evaluate the options: \begin{itemize} \item ASCII (American Standard Code for Information Interchange): The original standard ASCII uses 7 bits to represent 128 characters. However, \textit{Extended ASCII} uses 8 bits to represent 256 characters (including the original 128 plus additional symbols, accented letters, etc.). This 8-bit version became extremely widely used, especially before the broad adoption of Unicode. \item UNICODE: This is a modern character encoding standard designed to encompass characters from almost all writing systems. Common Unicode encodings like UTF-8 are variable-length (using 1 to 4 bytes, i.e., 8 to 32 bits, per character) and UTF-16 uses 2 or 4 bytes. While extremely widely used today, it doesn't represent every character as a unique 8-bit code (only the basic ASCII characters in UTF-8). UTF-32 uses 32 bits per character. \item BCD (Binary Coded Decimal): This code represents decimal digits (0-9) using a fixed number of binary bits (typically 4 bits per digit). It is not used for representing general characters (letters, symbols). \end{itemize} Step 3: Conclusion: Based on the definition of a code that represents each character as a unique 8-bit code and was historically (and still is in many contexts) the most widely used standard fitting this specific description, (Extended) ASCII is the best fit. While Unicode is more widely used overall now, its common forms are not strictly 8-bit per character for all characters. BCD is irrelevant for general character encoding.