Digital information: bits, sampling and storage
Grade 11 Science Worksheet
Circle the best answer, or write your answer on the line.
Sound is sampled 44100 times a second at 16 bits per sample on 2 channels, for 60 s. How big is the file in MB (1 MB = 10⁶ bytes), to 0.01, Ari?
Sound is sampled 48000 times a second at 16 bits per sample on 1 channel, for 60 s. How big is the file in MB (1 MB = 10⁶ bytes), to 0.01, Bo?
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SI and binary prefixes for bytes (NIST)
Prefix Symbol Bytes kilobyte kB 1000 kibibyte KiB 1024 megabyte MB 1000000 mebibyte MiB 1048576 gigabyte GB 1000000000 gibibyte GiB 1073741824 Using the table, how many bytes are in 1 MiB, Jun?
- 1024
- 1048576
- 1000000
Using the table, which is bigger, 1 GB or 1 GiB, Kira?
- 1 GiB, by about 7%
- 1 GB, by about 7%
- They are exactly equal
Using the table, why does a 500 GB drive show about 466 on some computers, Luz?
- Files shrink on the drive
- They count in GiB
- Some of its bytes leaked away over time
A sound's highest pitch is 5,000 Hz. What sampling rate is needed to record it faithfully, Milo?
- More than 10,000 a second
- About 2,500 a second
- About 5,000 a second, the same
CD audio samples 44,100 times a second (Library of Congress). About what is the highest pitch it can hold, Noah?
- About 88,200 Hz
- About 22,050 Hz
- About 44,100 Hz
Why do people keep a backup of important files in a second place, Ren?
- Backups make files smaller
- One drive may fail
- Files expire after a year
What helps protect stored files from theft, Tala?
- A strong password and encryption
- Giving the files new names
- Saving two copies on one drive
Why can a file be compressed to take less space, Zee?
- Compression deletes the whole file
- Patterns can be stored more briefly
- Each of the bits gets physically smaller