Two isolated conducting components, X and Y, are inside a vacuum chamber. They do not touch.
The table gives information about their charges and the movement of electrons.
| Event | Charge / magnitude of charge in nC\mathrm{nC}nC |
|---|---|
| initial charge on X | +7 |
| electrons move onto X | 11 |
| electrons then move away from X | 5 |
| charge on Y after these events | -4 |
After both electron movements, X and Y are brought close together.
Calculate the final charge on X.
Explain whether X and Y attract or repel each other.
91 exam-style questions on Edexcel GCSE Physics 11.1 Charging by friction, covering 11.1.1 Charging insulators by friction, 11.1.2 Forces between charges, 11.1.3 Electrostatic phenomena, and 11.1.4 Earthing and removing charge. Each one has a worked solution and a mark scheme showing where the marks go.