Presentation on theme: "Magnetism & Electromagnetism"— Presentation transcript:
1 Magnetism & Electromagnetism Test ReviewMagnetism & Electromagnetism
2 1. What are the 3 metals that are ferromagnetic? iron, nickel, and cobalt2. The reason a magnet can attract an un-magnetized nail is that nails become ( temporarily / permanently ) magnetized in a magnetic field.temporarily3. How does an iron rod become magnetic?When the net spin of its electrons point in the same direction.
3 4. Where is the magnetic field strength the strongest in a magnet 4. Where is the magnetic field strength the strongest in a magnet? at the poles 5. Earth’s geographic North Pole of the earth is close to its magnetic _______ pole. South 6. Which pole of a compass needle points to the south pole of a magnet? North
4 7. What are magnetic domains. Regions of atoms magnetically aligned. 8 7. What are magnetic domains? Regions of atoms magnetically aligned. 8. If you break a bar magnet in half, what happens to the 2 halves? You get 2 bar magnets with 2 poles 9. How are magnetic field lines surrounding a magnet conventionally drawn? From south to north OR From north to south From north to south
5 10. The picture below shows the magnetic field of 2 magnets, a ___ pole on the right and a ____ pole on the left. North; North 11. The picture below shows the magnetic field of 2 magnets, a ____ pole on the right and a ____ pole on the left. North; South 12. If the opposite poles of magnets are brought near each other, what will happen? They will attract
6 13. If 2 like poles of a magnet are brought near each other, what will happen? They will repel 14. If you put a compass in a magnetic field, the compass will line up ( randomly / parallel / perpendicular ) to the magnetic field lines. parallel
7 15 b. Where is the direction of the current in the wire directed? down 15 a. Where is the magnetic field the strongest?At Point A15 b. Where is the direction of the current in the wire directed?down16. If you bent the wire into a loop, like the picture to the right, where is the magnetic field the strongest?at the center
8 17. What do you need to make an electromagnet 17. What do you need to make an electromagnet? battery, wire, and a nail 18. What is electromagnetic induction? Inducing voltage by changing the magnet field around a conductor. 19. The magnetic field strength of an electromagnet will be greater if the wire’s ( resistance / temperature / current ) is increased. current
9 20. The magnetic field strength of an electromagnet will be decreased if the number of coils of a solenoid is ( increased / decreased / stays the same ). decreased 21. The magnetic field strength of an electromagnet will be greater if the curled wire encloses ( a wooden block / an iron rod ). an iron rod 22. Using the 1st right hand rule, where does your thumb point? in the direction of the conventional current.
10 23. Electricity is transmitted from the power plant to your home using ( AC / DC ) circuits. AC 24. Label where the north pole would be in the electromagnet illustrations?NN
11 25. Magnetic fields could be produced by particles that are ___. a. Moving and neutral b. moving and chargedc. Stationary and charged d. stationary and neutralb. moving and charged26. When a loop of wire is rotated, like in the magnetic field shown, what is produced in the wire?a current27. A transformer works due to the mutual induction created by a changing _________ __________.magnetic field
12 28. A generator converts ( potential / kinetic ) energy into ( electrical / mechanical ) energy. kinetic; electrical 29. What is the energy source of a generator? turbine; also has a magnet & a coil of wire 30. A device that transforms electrical energy to kinetic energy is a ( generator / transformer / motor). motor
13 31. A device that uses 2 coils around an iron core to change the voltage across a circuit is called a ( generator / transformer / motor ).transformer32. Transformers ( increase / decrease ) the current in the transmission lines to reduce the risk of electric shock in your home.decrease33. In the transmission of electricity, electricity is transmitted at a ______ voltage and ______ current.high; low
14 34. A step-down transformer ( increases / decreases) voltage. 35. In a fossil fuel power plant, ( water / wind / steam) turns the turbine.steam