for second block

4. which are devices that use an electromagnet to measure electric current.
7. contain two or more branches for current to move through.
12. is a temporary magnet made by wrapping a wire coil carrying a current around an iron core.
13. reverses the direction of the current in a regular pattern.
14. the group of atoms with aligned magnetic poles.
16. is a device that changes electrical energy into mechanical energy.
17. a single wire wrapped into a cylindrical wire coil.

1. are where the magnetic forces exerted by the magnet is strongest.
2. uses electromagnetic induction to transform mechanical energy into electrical.
3. exerts a force on other magnets and objects made of magnetic materials.
5. refers to the properties and interactions of magnets.
6. is related to the force that causes electric charges to flow.
8. the generation of a current by a changing magnetic field.
9. the coils in these generators have many coils of wire wrapped around huge iron cores.
10. the rate at which electrical energy is converted to thermal energy.
11. the net movement of electric charges in a single direction.
15. is a device that increases or decreases the voltage of an alternating current.