When two insulating materials are rubbed, electrons move from one material to the other. The material with the negatively charged electrons becomes negatively charged. The one that has lost the electrons becomes positively charged.
Two objects that have opposite charges attract and same charges repel.
We are expected to know electric circuit symbols. They are available on page 52 of the AQA revision guide. Otherwise, they are shown here: http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa/electricity/circuitsrev1.shtml
Current = Charge/time in seconds
Ammeters are always placed in series with the component. This is how current is measured, and is shown in amps (I).
Voltmeters are always placed in parallel with the component. This is how potential difference is measured, and is shown in volts (V).
Whenever these 3 of one are expected and 2 are given, use this equation:
Potential Difference = Work Done or Energy Transferred / Charge
If you need to work out resistance, use this equation:
Resistance = Potential Difference / Current
Ohm's Law says that potential difference and current are directly proportional…