Storage media classification – identifying non-magnetic technologies Which of the following is not a magnetic storage device?
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AMagnetic disk
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BMagnetic tape
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CMagneto-optical disk
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DOptical disk
Answer
Correct Answer: Optical disk
Explanation
Introduction / Context:Digital storage technologies are often grouped by their recording physics: magnetic, optical, and solid-state. Knowing the differences helps when discussing durability, rewrite cycles, and performance.
Given Data / Assumptions:
- We compare representative devices against the “magnetic” category.
- Optical media encode data via pits/lands and reflectivity changes.
Concept / Approach:Magnetic disk (HDD) and magnetic tape store data by magnetizing domains. Magneto-optical (MO) uses a laser to heat spots while a magnetic field sets polarity—hybrid but fundamentally uses magnetization to write. A pure optical disk (CD/DVD) uses physical/reflective features without magnetic fields; thus it is not magnetic storage.
Step-by-Step Solution:
Identify which option lacks magnetic recording: optical disk.Confirm others rely on magnetization.Choose “Optical disk.”Verification / Alternative check:Technical descriptions of CDs/DVDs/Blu-ray emphasize pits, lands, and reflectivity changes, not magnetic domains.
Why Other Options Are Wrong:
- Magnetic disk: Magnetic storage.
- Magnetic tape: Magnetic storage.
- Magneto-optical disk: Uses magnetic writing with optical assistance, therefore magnetic-based.
Common Pitfalls:
- Confusing “optical” with “magneto-optical.” They are different categories.
Final Answer:Optical disk