Which of the following statement(s) is/are not true about magnetic tapes? I. Direct access device II. Store large volume of data III. Use for backup purpose
Only I
Understanding Magnetic Tapes: Access, Capacity, and Usage
Let's analyze each statement about magnetic tapes to determine which ones are not true. Magnetic tapes are a form of sequential access data storage.
Analyzing Statement I: Direct Access Device
Statement I says magnetic tapes are a direct access device. Let's understand what direct access means.
- Direct Access: In direct access (also known as random access), the storage device can access any piece of data directly, regardless of where it is located physically on the medium. Examples include hard disk drives (HDD), solid-state drives (SSD), and RAM.
- Sequential Access: In sequential access, data must be accessed in the specific order in which it was written. To reach a specific piece of data, you must read through all the data that comes before it.
Magnetic tapes work by winding a tape past a read/write head. To find a specific file or block of data, the tape must be spooled forward or backward sequentially until the desired location is reached. This is the definition of sequential access, not direct access.
Therefore, statement I, "Direct access device", is not true about magnetic tapes.
Analyzing Statement II: Store Large Volume of Data
Statement II says magnetic tapes store a large volume of data.
Historically and currently, magnetic tapes are well-known for their high storage capacity relative to their cost, especially for large-scale data storage. Modern tape formats (like LTO) can store many terabytes of data on a single cartridge.
Therefore, statement II, "Store large volume of data", is true about magnetic tapes.
Analyzing Statement III: Use for Backup Purpose
Statement III says magnetic tapes are used for backup purpose.
Magnetic tapes have been a primary medium for data backup and archiving for decades. Their high capacity, low cost per gigabyte, long archival life, and reliability make them suitable for storing copies of data for disaster recovery and long-term retention.
Therefore, statement III, "Use for backup purpose", is true about magnetic tapes.
Identifying the Incorrect Statement(s)
Based on our analysis:
- Statement I: Not true (Magnetic tapes are sequential access).
- Statement II: True (Magnetic tapes store large volumes of data).
- Statement III: True (Magnetic tapes are used for backup).
The question asks which statement(s) is/are not true. Only statement I is not true.
The correct option is the one that indicates only statement I is not true.
Summary of Statements
| Statement | Description | True/Not True? |
|---|---|---|
| I. Direct access device | Can access any data location directly. | Not True (It's sequential access) |
| II. Store large volume of data | Can hold significant amounts of data. | True |
| III. Use for backup purpose | Commonly used for creating data backups. | True |
Thus, only statement I is not true about magnetic tapes.
Revision Table: Key Facts about Magnetic Tapes
| Feature | Description |
|---|---|
| Access Method | Sequential Access (Data must be read in order) |
| Capacity | High (Can store large volumes of data) |
| Common Use Cases | Data Backup, Archiving, Data Interchange |
| Cost | Generally low cost per gigabyte, especially for large capacity |
Additional Information: Sequential vs. Direct Access
Understanding the difference between sequential and direct access is crucial for classifying storage devices:
- Sequential Access: Think of a cassette tape or a reel of film. To get to a song or scene in the middle, you have to fast-forward through everything before it. Data is accessed in a fixed order. Magnetic tapes and older technologies like punched cards use sequential access. This is slower for retrieving individual pieces of data but can be efficient for reading large blocks of data in order.
- Direct Access (Random Access): Think of a CD, DVD, hard drive, or USB drive. You can jump directly to any track, file, or location without having to go through the data preceding it. Data can be accessed non-sequentially. This is much faster for retrieving specific data points randomly.
Magnetic tapes are well-suited for applications where data is processed in batches or where the primary need is cost-effective, high-capacity storage for backups and archives that aren't accessed frequently for random reads.
Important Questions from Secondary Memory
Which of the following can be said about primary storage in comparison with secondary storage?
__________ is the time taken to locate the disk arm to a specified track for data read/write.
For a magnetic disk with concentric circular tracks, the seek latency is not linearly proportional to the seek distance due to
If one track of data can be transferred per revolution, then what is the data transfer rate ?
Given below are two statements:
Statement I: The disk has a total number of 2000 cylinders.
Statement II: 51200 bytes is not a valid block size for the disk.
In the light of the above statements, choose the correct answer from the options given below:
