Lesson 1.2.5
1.2.5 Compression Quiz: OCR Computer Science, Unit 2
20 questions
In partnership with Revision Ninja
Lesson 1.2.5, Compression: 20 multiple choice questions for the OCR GCSE Computer Science (J277), Unit 2: Memory and storage, written with Revision Ninja.
Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.
The 20 questions
-
What is the primary purpose of file compression?
- Improve resolution
- Reduce file size
- Convert formats
- Increase security
-
Which compression type permanently removes some data to reduce file size?
- Lossless
- Run-length
- Lossy
- Huffman
-
Which compression type allows the exact original file to be restored?
- Truncated
- Destructive
- Lossless
- Lossy
-
Which file format is commonly associated with lossy compression of images?
- Plain text (TXT)
- PNG
- ZIP
- JPEG
-
Which of these is a common example of lossless compression?
- Streaming video
- ZIP archive
- JPEG image
- MP3 audio
-
What is a major disadvantage of lossy compression?
- Larger file size
- Slower transmission
- Permanent quality loss
- Requires more RAM
-
What is a typical disadvantage of lossless compression compared to lossy?
- Lower resolution
- Larger file sizes
- Blurry images
- Muffled audio
-
In which network scenario is file compression most useful?
- Fast fibre
- High security
- Limited bandwidth
- Local storage
-
Which compression method is best for an emailed photo where minor detail loss is fine?
- No compression
- Lossless compression
- Lossy compression
- Encryption
-
Which compression type is essential for medical scans where every detail matters?
- Truncated
- Lossy
- Destructive
- Lossless
-
A user compresses an audio file, which becomes much smaller, but some sound is missing. What type of compression was used?
- Defragmentation
- Encryption
- Lossless
- Lossy
-
Source code for a program must be compressed and then restored exactly. Which type should be used?
- Lossless compression
- Lossy compression
- Sound compression only
- Image compression only
-
Why compress files before sending them over a slow network?
- Reduce transfer time
- Add metadata
- Encrypt data
- Increase quality
-
What happens when a file is compressed using lossy compression and then compressed again?
- Further quality loss
- File size increases
- No change occurs
- Original quality restored
-
What is a main disadvantage of data compression?
- Increased file size
- Extra processing time
- Permanent data security
- Hardware incompatibility
-
Which storage or transfer scenario benefits most from lossy compression?
- Streaming video
- Source code files
- Financial spreadsheets
- Database backups
-
What size is a 10 MB file after being compressed losslessly and then decompressed?
- 6 MB
- 0 MB
- 10 MB
- 14 MB
-
What trade-off does lossy video streaming make to save bandwidth?
- Higher audio fidelity
- Slower download speed
- Lower picture quality
- Larger file size
-
How should a photo archive keep originals while sharing easily online?
- Keep lossless originals
- Use lossy only
- Delete originals
- Print copies
-
What is a key benefit of lossless compression compared to lossy compression?
- Exact data restoration
- Faster compression speed
- Much smaller files
- Lower processing load
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