A student investigates static electricity using a plastic balloon.
a.[2]
Explain in terms of electrons why the balloon is not normally charged.
b.[2]
Explain in terms of electrons why the balloon becomes charged when the student rubs it against a woolen jumper.
c.[2]
The diagram shows the electric field between two charges, C and D.
State the charges of C and D.
Use the diagram to explain your answer.
d.[1]
Describe one similarity between the electric field line diagram and a magnetic field line diagram for a bar magnet.
e.[2]
Calculate the charge when 180 J of energy is transferred with a potential difference of 12 V.
Use the equation:
energy transferred=charge×potential difference \text{energy transferred} = \text{charge} \times \text{potential difference} energy transferred=charge×potential difference