Question Constellation Sign up for free AQA · GCSE · Computer Science · Higher
Minimum file size for the recording calculation
Calculate the minimum file size for the recording. Give your answer in megabytes. You should show your working.
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Marking points
- 1 Converts the recording time to 480 seconds.
- 2 Calculates the bit total using sampling rate multiplied by sample resolution and duration.
- 3 Converts bits to bytes by dividing by 8.
- 4 Converts bytes to megabytes by dividing by 1 000 000 and gives 6 MB.
Full-mark answer
8 minutes = 480 seconds. 25 000 x 4 x 480 = 48 000 000 bits. 48 000 000 / 8 = 6 000 000 bytes. 6 000 000 / 1 000 000 = 6 megabytes.
Why this answer loses marks
Multiplies the rate by the sample size but leaves the result in bits.
The working also needs the recording duration and the bit-to-byte and byte-to-megabyte conversions.