A student holds a metal rod in her hand and rubs it with a dry cloth.
The rod does not stay charged.
Which statement explains why?
Charge flows through the metal and her body, so it does not build up
Metals contain no electrons, so no charge can be moved by rubbing
The cloth only transfers protons, which cannot move into metals
Rubbing only charges objects that already carry some charge
43 exam-style questions on OCR GCSE Physics 3.1 Static and charge, covering 3.1.1 Positive and negative charge, 3.1.2 Static electricity and forces between charged objects, 3.1.3 Electron transfer and static electricity, 3.1.4 Electric fields, 3.1.5 Current as a flow of charge, 3.1.6 Current in a single closed loop, and 3.1.7 Charge, current and time. Each one has a worked solution and a mark scheme showing where the marks go.