Plex
Paging drum
Card punch
Optical mark reader E. None of the above
Answer is Wrong!
Answer is Right!
The correct answer is: B. Paging drum
A paging drum is a type of magnetic drum used as a secondary storage device in early computers. It is a cylindrical drum with a magnetic surface on which data can be stored. The drum is rotated at high speed, and data is read and written to the surface using a read/write head.
A paging drum is used to hold the images of pages in main memory. When a page is needed, it is read from the paging drum and transferred to main memory. When a page is no longer needed, it is written back to the paging drum.
The other options are incorrect for the following reasons:
- Plex is a type of computer memory that is used to store data that is frequently accessed. It is not used to store the images of pages in main memory.
- A card punch is a device that is used to punch holes in cards. It is not used to store the images of pages in main memory.
- An optical mark reader is a device that is used to read marks on paper. It is not used to store the images of pages in main memory.