Which of the following is a sequential access device?

Appeared in: NHM UP Staff Nurse-2023 Shift-2nd

Explanation

Sequential access devices read and write data in a linear, ordered sequence from the beginning.
Magnetic tape is the classic example of a sequential access medium, functioning like an audio cassette where one must pass through all preceding data to reach a specific point.
This access method makes magnetic tape slow for retrieving specific files but cost-effective for large-scale data backups and long-term archiving.

Option B: Magnetic disks are direct access (or random access) devices. The read/write head can move directly to any specific track and sector, allowing for non-linear data retrieval.
Option C: A hard disk is a specific type of magnetic disk and is a direct access device. It uses spinning platters and a moving arm to quickly access data at any location on the disk.
Option D: Solid-state drives (SSDs) use flash memory with no moving parts, providing extremely fast direct access to any data block. They are a modern example of a random-access device.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Storage Access Methods in Computer Systems as background academic context rather than a clinical decision trigger.
Understanding data storage types is relevant in healthcare for managing large volumes of patient data in Electronic Health Records (EHRs).
Sequential access devices like magnetic tapes are often used for long-term, low-cost archival of medical records, lab results, and imaging data that do not require frequent, immediate access.
Direct access devices like SSDs and hard drives are essential for active patient databases where fast retrieval of information is critical for clinical decision-making at the point of care.

How to Approach the Question

First, identify the key term in the question: 'sequential access'.
Recall the definition of sequential access: data is read or written in a specific, linear order from beginning to end.
Think of a real-world analogy, like a movie on a VHS tape. To watch a scene in the middle, you must fast-forward through the beginning of the tape.
Evaluate each option against this definition. Magnetic disks, hard disks, and SSDs all allow you to 'jump' directly to the data you need, which is known as 'direct' or 'random' access.
Conclude that only magnetic tape operates in a purely linear, sequential manner, making it the correct choice.

Concept Tested & Keywords

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E6 Essentials of Educational Technology Nursing EducationL Gopichandran C Kanniammal (pp 39-344 of 355) pp. 200-202, 201-203

Practise the full NHM UP Staff Nurse-2023 Shift-2nd

Attempt every question from this paper in a timed mock, then review the full solution for each one.