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A computer records an audio file of someone playing a guitar - OCR - GCSE Computer Science - Question 4 - 2019 - Paper 1
Question 4
A computer records an audio file of someone playing a guitar. (a) Describe what happens when the computer converts the music into a file. (b) The sample rate is... show full transcript
Worked Solution & Example Answer:A computer records an audio file of someone playing a guitar - OCR - GCSE Computer Science - Question 4 - 2019 - Paper 1
Step 1
Describe what happens when the computer converts the music into a file.
Answer
When the computer converts music into a file, it processes the sound waves generated by the guitar into a digital format. This involves sampling the analog signal at regular intervals, where each sample represents the sound wave's amplitude at that moment. These amplitudes are then quantized into discrete values, which are encoded in a numerical format. The resulting data is stored in a file format, such as WAV or MP3, which can be later retrieved and played back by the computer or other devices.
Step 2
Give two effects this will have on the recording.
Answer
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Increasing the sample rate results in higher audio fidelity, allowing for more accurate representation of the original sound by capturing more detail in the sound wave.
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A higher sample rate also increases the file size of the recording, as more samples are taken per second, leading to more data being stored.
Step 3
Convert the binary number 11001011 into denary.
Answer
The binary number 11001011 converts to denary as follows:
To calculate this, we can break it down into powers of 2:
- 1 × 2^7 = 128
- 1 × 2^6 = 64
- 0 × 2^5 = 0
- 0 × 2^4 = 0
- 1 × 2^3 = 8
- 0 × 2^2 = 0
- 1 × 2^1 = 2
- 1 × 2^0 = 1
Adding these gives: 128 + 64 + 0 + 0 + 8 + 0 + 2 + 1 = 195. Therefore, 11001011 in denary is 203.