Text, Sound & Images (Cambridge International IGCSE Computer Science): Exam Questions

Extract:

• Accept an obvious typo for "more bits" that still conveys more bits per character (e.g. "for bits" for "more bits").

The Unicode character set is used to represent text that is typed into a computer.

One disadvantage of using the Unicode character set, instead of the ASCII character set, is that the text stored takes up more storage space.

Give one reason why it takes up more storage space.

Jack has an MP3 file stored on his computer

Tick (✓) to show which type of data is stored in an MP3 file.

A student has a sound file that is too large to be stored on their external secondary storage device. The student compresses the sound file to make the file size smaller.

The compression method used reduces the sample rate and the sample resolution of the sound file.

State what is meant by the sample rate and sample resolution.

A logo is stored as a bitmap image.

Each square in the image represents one pixel, with three different colours being used in the image.

State what is meant by the term image resolution.

A music producer is working on a digital recording project. They need to understand the technical specifications of their audio files to ensure optimal quality for different distribution platforms.

The producer notices that their recording software allows them to adjust two key parameters when capturing audio: the sample rate and the sample resolution.

State what is meant by the sample rate and sample resolution.

Extract:

• Award the first mark for "set/list of characters" together with any idea of being defined/used/represented by a computer system, hardware or software (e.g. "characters defined by computer hardware and software").
• Award the second mark for "unique binary set/code", "unique number" or "unique code" as equivalents of "unique value".

The Unicode character set is used to represent text that is typed into a computer.

Describe what is meant by a character set.

A student is creating a range of documents for a school project.

The student records a podcast about computer science.

Describe how an analogue sound wave is converted into digital form.

Tick (✓) one or more boxes on each row to identify the effect(s) that each change will have on the sound file.

Discuss the trade-offs between image quality and file size when choosing a bitmap image's resolution and colour depth.

Provide examples to illustrate your answer.