c8 4-1 Compression - GCSE Quiz

What is file compression? Choose two statements that are true.

• It reduces the file size of one or more data files.
• It does this by grouping files together into a single file so they are easier to send.
• It can be either lossy or lossless.
• It does this by deleting unwanted data from a file.

Hamzah needs to email a large file to a classmate. Why might he need to use file compression to do so?

• Email services often only let you send compressed data files.
• Compressed files are less likely to become corrupted when being transferred via email.
• Email services often have maximum file sizes that prevent you sending files that are too large.
• He won't need to. All email providers let you send any files you like, regardless of size.

What type of compression actually deletes data and cannot be decompressed?

• File Compression
• Lossless Compression
• Lossy Compression
• Archive Compression

Lossy compression is most commonly used with images, video & audio files.

• True
• False

Which of the following is a benefit of lossy compression over lossless?

• File sizes will always be reduced, even when compressed multiple times.
• File quality is not harmed, e.g. images will look exactly the same.
• Files can be decompressed back to their original uncompressed form.
• File sizes are usually significantly smaller.

File archive software uses lossless compression to reduce the file size of one or more data files in a folder.

• True
• False

How does lossy compression reduce the size of image files?

• Through grouping repeated data together.
• By reducing the number of colours being used.
• By grouping files into a single folder.
• By replacing blocks of data with more compact versions.

Which two of the following file types use lossless compression?

• JPG
• PNG
• MP3
• ZIP