I'm a British high school student (doing a certificate called A levels) and question 16 in this past paper (1st Link ) is baffling me. The answers to the questions are on the mark scheme (2nd Link). I want someone to please explain the scenario for me. Part (b)i) is the hard part. The circuit is shown in part (c) of the question. I've done 10 hours of solid work on this question, and I have an idea of what the answer may be, but I'm finding it hard to articulate my thoughts because I keep running into too many inconsistencies.
Here is what I would like to kindly ask an answer for:
May someone please explain the graph describing the variation in the voltage of the D.C power supply?
May someone please answer part (b)i) in a more coherent form than the mark scheme? (This is the most important question of all.) Qualitative analyses are preferable, but mathematical ones are welcome if that is how you think.
May someone please explain how the graph in part (c) of the question arises?