Across
- 2. Electrical energy is transferred to thermal energy when current does work against a resistance. In metals this is a result of collisions between electrons and ions.
- 6. The unit of current.
- 7. A measure of the opposition to current flow.
- 10. A material that allows electrical charge to flow easily. Metals are particularly good conductors due to the free electrons in their structures.
- 12. The unit of potential difference (voltage). One volt is equal to one joule per coulomb.
- 14. The unit of power.
- 15. The current flowing through an Ohmic conductor at constant temperature is directly proportional to the potential difference (voltage) across it.
- 20. Current flow consisting of charges that continually change direction. These oscillations usually occur at a set frequency.
- 21. A material that doesn’t allow electrical charge to flow.
- 22. The total resistance is equal to the sum of the resistances of the individual resistors.
- 23. A safety device consisting of a thin metal filament that melts and cuts off the power supply if there is a surge in current. Fuses are connected to the live wire.
- 26. The blue coloured wire that completes the circuit in a mains power supply.
- 27. A device connected in series with a component to measure the current that flows through it.
- 28. A component that only allows current to flow through in the forward direction. They have very large resistances in the reverse direction.
- 29. A temperature dependent component, whose resistance increases as its temperature decreases.
Down
- 1. A conductor whose current flow is directly proportional to the potential difference (voltage) across it, when held at a constant temperature.
- 3. Components connected in parallel have the same potential difference (voltage) across each component. The total current is equal to the sum of the currents flowing through each component.
- 4. The total resistance is less than the lowest individual resistance.
- 5. A light sensitive component whose resistance decreases as its temperature increases.
- 8. The energy that is transferred per unit charge between two points in a circuit. It is often also called a voltage.
- 9. A device that is connected in parallel with a component to measure the potential difference (voltage) across it.
- 11. A light emitting component consisting of an enclosed metal filament. Its resistance increases as the filament’s temperature increases.
- 13. A device that gives out light when a current flows through it. Current can only flow through it in one direction, and a minimum voltage must be applied across it before it illuminates.
- 15. The unit of resistance.
- 16. Components connected in series have the same current passing through each component but share the total potential difference (voltage) of the power supply.
- 17. The unit of charge.
- 18. The rate of flow of electrical charge. Its value is the same at any position in a single closed loop. In metals, the charges that flow are electrons.
- 19. Current flow consisting of charges flowing in a single direction only. Batteries and cells provide direct current.
- 24. The rate at which an appliance transfers energy. For a circuit component, it is equal to the product of the current passing through it and the potential difference across it.
- 25. An a.c supply, which in the UK has a frequency of 50Hz a value of 230V.