I'm getting very confused which resistors, diodes and fixed resistors I need to buy for this prac. If you do AQA which size do you buy ? Which sort of diode is best to use? Is a metal film resistor better than a wirewound one or vica versa? AQA's worksheets are not very clear (unless I'm not looking properly!) Not really a physicsy person and we only have chem and bio specialists in the dept so any ideas and suggestions would be appreciated. Thanks.