Disk geometry fundamentals: In traditional PC storage formats, what is the standard size of a sector on a magnetic hard disk?
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A512 bytes
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B256 bytes
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C1024 bytes
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D512 Kb
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ENone of the above
Answer
Correct Answer: 512 bytes
Explanation
Introduction / Context:Understanding sector size helps with low-level disk utilities, partition alignment, and data recovery. For decades, the de facto standard sector size on PC-class hard disks has been 512 bytes, even as logical block size abstraction evolved.
Given Data / Assumptions:
- Conventional MBR-era drives used 512-byte sectors.
- Advanced Format drives may expose 4K physical sectors but still emulate 512-byte logical blocks.
- The question asks the standard, widely taught sector size.
Concept / Approach:
Sector size is the minimum addressable logical block on legacy disks. While modern Advanced Format introduces 4096-byte physical sectors, logical 512-byte addressing remains common for compatibility. Therefore, the standard sector size answer in entry-level PC tech contexts is 512 bytes.
Step-by-Step Solution:
Recall legacy PC conventions: sector = 512 bytes.Note that 256 and 1024 bytes are not standard legacy sector sizes for PCs.512 Kb is far larger than a single sector.Select 512 bytes as the correct value.Verification / Alternative check:
Disk utilities (fdisk-like tools) and OS APIs traditionally report 512-byte logical sector sizes unless specifically configured otherwise.
Why Other Options Are Wrong:
- 256 bytes / 1024 bytes: not the established PC sector standard.
- 512 Kb: six orders of magnitude larger than legacy sector size.
- None of the above: incorrect since 512 bytes is right.
Common Pitfalls:
Confusing physical 4K sectors with logical emulation; mixing filesystem cluster sizes (which are larger) with disk sector size.
Final Answer:
512 bytes