omputer-science/aqa/questions","basePath":"/gcse/computer-science/aqa/representing-sound/questions","formulaUrl":null,"initialIndex":22,"initialQuestionWindow":[{"id":"978e77ec-7113-4741-bd9a-401624f1baf3","revisionId":"4512e5d9-6c3a-40ee-a6fb-8afd10ad8cbe","questionNumber":null,"questionType":"LA","specification":"A podcaster is recording a short audio intro. The recording software uses a sampling rate of 3,000 Hz and a sample resolution of 12 bits.","difficulty":3,"difficultyBand":"medium","totalMarks":4,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"321dda07-cd68-4695-be42-ee7de6427e75","label":null,"content":"Calculate the minimum file size of a 10-second audio recording. Give your answer in bytes.\n\nYou should show your working.","markscheme":"- Shows correct multiplication of values: $3,000 \\times 12 \\times 10$ M1\n- Calculates the correct size in bits: $360,000$ bits A1\n- Shows division by 8 to convert to bytes: $360,000 \\div 8$ M1\n- Obtains the correct final answer: $45,000$ bytes A1","marks":4,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"97a415c5-9d1d-44a2-ae84-a50ca2cba263","revisionId":"30b6e799-14d2-4b87-942e-ed23305ee924","questionNumber":null,"questionType":"LA","specification":"A marine biologist is recording underwater whale vocalizations using a specialized hydrophone. The single-channel (mono) audio is captured with a sampling rate of 12,000 Hz and a sample resolution of 24 bits.","difficulty":3,"difficultyBand":"medium","totalMarks":4,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"2ce32292-78e1-41e8-bfcd-5934225c3ee7","label":null,"content":"Calculate the minimum file size of a 15-second audio recording. Give your answer in **bytes**.\n\nYou should show your working.","markscheme":"- Shows substitution of correct values into the file size formula: $12,000 \\times 24 \\times 15$ (or equivalent) M1\n- Calculates the correct intermediate value, either the total bits ($4,320,000$ bits) or converts the resolution to bytes ($24 \\div 8 = 3$ bytes) A1\n- Shows division by 8 to convert bits to bytes (e.g. $4,320,000 \\div 8$) OR shows direct multiplication of bytes (e.g. $12,000 \\times 3 \\times 15$) M1\n- State the correct final answer of $540,000$ (or $540,000$ bytes) A1","marks":4,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"995a0e6d-66d4-49b7-bf57-11af4a072d9b","revisionId":"363163a8-990a-4c87-919c-92f62d776494","questionNumber":null,"questionType":"LA","specification":"A bioacoustics researcher records the low-frequency vocalisation of a blue whale using a single-channel hydrophone.\n\nThe recording is configured with a sampling rate of 48,000 Hz and a sample resolution of 24 bits. The captured sound clip lasts for exactly 250 seconds.","difficulty":4,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"065e7d33-ee70-4937-ba93-ca810cf144a5","label":null,"content":"Calculate the minimum file size of the recording in megabytes (MB).\n\nAssume 1 kilobyte (kB) = 1,000 bytes and 1 megabyte (MB) = 1,000,000 bytes.\n\nYou must show your working.","markscheme":"- Calculates the total size in bits by multiplying the parameters: $48,000 \\times 24 \\times 250 = 288,000,000$ bits M1\n- Converts the size from bits to bytes by dividing by 8 (or by converting 24 bits to 3 bytes early: $48,000 \\times 3 \\times 250$): $36,000,000$ bytes M1\n- Converts the bytes to megabytes by dividing by $1,000,000$ to get $36$ MB A1","marks":3,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null}],"subjectCode":"gcse_computer_science__aqa","summaries":[{"id":"00e5fca2-2c20-4361-ad53-2845355ff80c","difficultyBand":"medium","calculatorUse":null},{"id":"03757f99

Representing sound

Question 9

Representing sound Questions

Representing sound

Question 9

Representing sound Questions