Which of the following is not a valid size of a FLOPPY DISK?
5 1/4" is not a valid size of a FLOPPY DISK.
What became the most common format, the double-sided, high-density (HD) 1.44 MB disk drive, shipped in 1986. The first Macintosh computers used single-sided 3½-inch floppy disks, but with 400 KB formatted capacity. These were followed in 1986 by double-sided 800 KB floppies.
Computers need a floppy drive to read floppy disks, and many modern computers are no longer supplied with a floppy disc drive because we now work with much larger files. ... In the past, floppy disks were used to: transfer small files of data from one machine to another. backup important small files stored on a hard disk.
The most popular type of floppy disk drive is the 3 ½-inch drive, which is still in limited use today. The floppy disk drive has been replaced by other types of drives such as CD drives, DVD drives as well as USB flash drives. There are many different types of floppy disk drives that have come and gone over the years.