Transcript Chapter 3
Chapter 3 Magnetism 1. The two ends of a solenoid act likePoles of a magnet 2. Magnetic poles that are alikeRepel each other 3. You can increase the strength of an electromagnet’s field byUsing a stronger ferromagnetic material for the core 4. As Earth’s magnetic poles move, the magnetic declination in a given location willChange 5. An electric current produces aMagnetic field 6. Magnetic poles that are unlikeAttract each other 7. A device uses to measure small currents is aGalvanometer 8. Every magnet, regardless of its shape, has twoMagnetic poles 9. What is one difference between a galvanometer and an electric motor? A galvanometer uses an electric current 10. To reverse the direction of current in a motor, current is conductedThrough the commutator to the armature 11. What device transforms electrical energy into mechanical energy? An electric motor 12. Magnetic field lines around a bar magnetSpread out from one pole and curve around another. 13. The type of current produced by a battery isdirect current 14. A device that increases or decreases voltage is called atransformer 15. Electric current from a generating plant isDirect current transmitted at high voltages, but usually used at low voltages 16. A solenoid with a ferromagnetic core is called anelectromagnet 17. A generator transformsMechanical energy into electrical energy 18.An magnet is any material that attracts iron and materials that contain iron. 19.A solenoid with a ferromagnetic core is called an electromagnet. 20. To generate electricity at an electric company, a turbine is attached to the armature of a generator. 21. A current consisting of charges that flow in one direction only is called a direct current. 22. A galvanometer is a device currents that measures small magnetic fields. 23. A magnetic field is produced around a wire through which a current flows. 24. A step-up transformer is a transformer that increases voltage. 25. A maglev train floats above its rails due to magnetism. 26. The distance that the pointer of a galvanometer moves depend on the amount of currents in the loops of the armature. 27. When a wire moves up and down repeatedly in a magnetic field, an alternating current is induced in the wire. 28. An electromagnet is a strong magnet that can be turned on and off. 29. When placed near each other, unlike magnetic poles attract each other. 30. A magnetic field is the region of magnetic force around a magnet.