Topic 10 + 12

4. brushes – Conductive parts that maintain contact in a motor with the split ring commutator (13)
5. – Unit of electric charge (7)
7. – Colour of the live wire in a UK plug (5)
8. – Unit of energy (6)
11. – Type of electric charge carried by protons (8)
14. – Component that allows current in one direction only (5)
15. – Flow of electric charge in a circuit (7)
18. wire – Wire that completes the circuit back to the supply (11)
21. – When two objects meet and exert forces on each other (9)
22. – Electrical potential difference between two points (7)
23. – Direction of magnetic field lines from a magnet (5)
24. wire – Safety wire that prevents electric shock (9)

1. field – Region where magnetic forces act (13)
2. – Safety device that melts if current is too high (4)
3. – Scientist linked to the left-hand rule for motors (7)
6. – Slope of a graph, often used for rate calculations (8)
9. – Type of circuit where components are in one loop (6)
10. ring commutator – Device that reverses current every half turn in a motor (21)
12. – SI unit of time (6)
13. – Circuit where components have separate branches (8)
16. – A resistor whose resistance changes with temperature (9)
17. – Opposition to the flow of current (10)
19. – Rate of energy transfer or work done (5)
20. effect – Force on a current-carrying wire in a magnetic field (11)