The correct answer is: E. All of the above are true.
A magnetic disk is a data storage device that uses magnetic fields to store and retrieve digital information. It is a type of secondary storage, which means that it is not directly accessible by the CPU. Instead, data must be read from or written to the disk by the disk controller.
Magnetic disks are typically used to store large amounts of data, such as operating systems, applications, and user files. They are also used to store data that needs to be accessed quickly, such as databases and web pages.
There are two main types of magnetic disks: hard disks and floppy disks. Hard disks are more expensive than floppy disks, but they have a much higher capacity. Floppy disks are less expensive than hard disks, but they have a much lower capacity.
Magnetic disks are a reliable and efficient way to store data. However, they are not without their limitations. One limitation is that they are susceptible to damage from physical shocks and magnetic fields. Another limitation is that they can only be accessed sequentially, which means that it can take a long time to access data that is not stored near the beginning of the disk.
Despite these limitations, magnetic disks are a popular choice for data storage. They are relatively inexpensive, they have a large capacity, and they are easy to use.
Here is a brief explanation of each option:
- Option A: It is expensive relative to magnetic tape. This is true. Magnetic disks are more expensive than magnetic tape, but they have a much higher capacity.
- Option B: It provides only sequential access to stored data. This is true. Magnetic disks can only be accessed sequentially, which means that it can take a long time to access data that is not stored near the beginning of the disk.
- Option C: Users can easily update records by writing over the old data. This is true. Users can easily update records by writing over the old data.
- Option D: It does not provide an automatic audit trail. This is true. Magnetic disks do not provide an automatic audit trail.
Therefore, the correct answer is: E. All of the above are true.