Quiz 17.4

DIRECTIONS: Read each question carefully. Then click on the dot next to the answer that most closely fits the question. Try to answer all questions on this quiz and when you are done, click on the grade me button at the bottom.

Coverage: Section 17.7

  1. How does an optical disk (CD-ROM) actually store 1s and 0s?
by the presence or absence of tiny holes called pits
by the direction of magnetization of regions of mylar coated with iron ferrite
by the type of polarization of tiny regions of shiny plastic

  1. Which storage method is used for CD-ROMs?
concentric tracks
one long spiral

  1. What happens if somebody scratches the surface of a CD-ROM?
it is ruined and the data is unrecoverable
it is ruined but the data can be retrieved by special means
it is likely still usable

  1. What is the speed of CD-ROMs compared to hard disks?
much faster
much slower
about the same speed

  1. Is binary data stored as plain 1s and 0s on CD-ROMs?
yes
no

  1. What is the typical storage capacity of a CD-ROM? (MB = megabyte)
1.5 MB
10 GB
680 MB

  1. Are CD-ROMs truly read only memories as their name implies?
yes, there is no way to change them
yes, but sometimes new files can replace old ones on the CD-ROM
no, you can read and write and write over old files

  1. What optical technology does a CD-ROM rely on?
lasers
radioactive emission
differential polarization