Edexcel 1CP2 2.2.4: Limits of binary representation
The free BugBot lesson that teach this point, a robot to try it on, and the past-paper questions that test it.
What it covers
Sound is a wave: air pressure rising and falling, smoothly and continuously. A computer can only store numbers, so to record sound it measures the wave at regular moments and stores each measurement as a binary number. That is sampling. In this lesson you sample a note, measure how much data it takes, and use the samples to work out which note it was and play it on BugBot's buzzer.
- Sampling a wave
- Bit depth
- File size
- From samples back to a note
- Quality and size
Or do it in the simulator, with tasks that mark themselves
Lessons that teach it
- F8.8 Sound Data representation
Sampling, sample rate, bit depth and file size, and finding a note from its samples.
Try it on a robot
The task from F8.8 Sound, running here. Change the program and press Run.
Past paper questions on this
Real exam questions that test this, each worked through with a program you can run.
The specification is Edexcel's own document; this page says which of our lessons teach point 2.2.4 and is not endorsed by the board.