Magnetic interference and data media: Why should floppy disks, hard drives, and magnetic tape (for example, VCR or cassette tapes) be kept away from loudspeakers and other strong magnets?

Introduction / Context:
Magnetic storage media rely on precisely oriented magnetic domains to encode data. External magnetic fields can disturb or erase these domains, causing data corruption or total data loss. Speakers contain permanent magnets and can create strong localized fields capable of damaging nearby media.

Given Data / Assumptions:

• Devices: floppy disks, magnetic hard drives, and tapes store data magnetically.
• Speakers and certain motors produce strong magnetic fields.
• We are distinguishing electromagnetic interference (EMI) from radio-frequency interference (RFI).

Concept / Approach:

EMI refers to unwanted electromagnetic effects that can disrupt operation or stored states. For magnetic media, static or slowly varying fields can reorient magnetic domains. RFI is a subset of EMI at radio frequencies affecting signal integrity; while RFI can cause noise, the primary risk to magnetic media near a magnet is direct magnetic disturbance—best categorized as EMI.

Step-by-Step Solution:

Verification / Alternative check:

Manufacturers warn against storing magnetic media near magnets. Testing with degaussing coils demonstrates how magnetic fields erase tapes and floppies.

Why Other Options Are Wrong:

• RFI: focuses on radio-frequency emissions, not the static magnetic fields that erase media.
• EXE / FYI / IOU: unrelated acronyms, included as distractors.

Common Pitfalls:

Confusing magnetic erasure with RF noise; assuming modern hard drives are immune (strong fields can still damage or confuse servo tracking if sufficiently close).

Final Answer:

EMI