Optical drives

Question 1

What is the storage capacity of a Compact Disc (CD)?

Answer 1

Stores 74 to 80 minutes of music or 650–700 MB of data.

Question 2

How much data can a DVD store?

Answer 2

Standard: 4.7 GB
Dual-layer (DL): 8.4 GB

Question 3

What is the storage capacity of a Blu-ray Disc (BD)?

Answer 3

Standard: 25 GB
Dual-layer (DL): 50 GB

Question 4

What are the categories of optical drives?

Answer 4

1. Read-only (ROM): Data cannot be altered (e.g., CD-ROM, DVD-ROM, BD-ROM).
2. Write-once (R): Data can be written once and not erased (e.g., CD-R, DVD-R, BD-R).
3. Write-many/Erasable (RW/RAM/RE): Data can be rewritten multiple times (e.g., CD-RW, DVD-RW, BD-RE).

Question 5

What is unique about CD-RW and DVD-RW discs?

Answer 5

They allow data to be erased and rewritten multiple times.

DVD-RAM, a variation of DVD-RW, has a different form factor but similar functionality.

Question 6

What is BD-RE?

Answer 6

Blu-ray Disc Erasable (BD-RE) is a rewriteable disc, allowing multiple rewrites similar to CD-RW or DVD-RW.

Question 7

How is the speed of an optical drive measured?

Answer 7

X-rating determines the transfer speed:
CD: 1X = 150 KB/s
DVD: 1X = 1.385 MB/s
Blu-ray: 1X = 4.5 MB/s

Question 8

What is the data transfer rate of a 52X CD drive?

Answer 8

52X × 150 KB/s = 7800 KB/s or 7.6 MB/s

Question 9

What does a dual-layer disc (e.g., DVD-DL, BD-DL) provide?

Answer 9

Double the standard storage capacity by using two physical layers for data storage.

Question 10

What is the primary difference between DVD-R and DVD+R?

Answer 10

Both are write-once discs, but DVD+R supports better error handling and compatibility with newer drives.