Bozo Bucket Review Chapter 21 Chapter 21

Rules of Game You and your teammates will each take turns answering review questions. If correct, your team will earn a point. You also will have a chance to shoot a paper wad into the trash bin from a designated distance. If you make your basket, your team will earn an additional one, two, or three points!

Questions 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Question 1 Earth’s magnetic field and a bar magnet both attract particles to the same locations. Where are they? A) the middle of the magnet B) all around the outside C) the North and South poles D) first to the middle, then to the ends

Question 2 What must happen for an electromagnet to have a magnetic field? A) It must be heated. B) It has to be touching another magnet. C) It must be lined up with Earth’s magnetic field. D) It must be connected to an electrical source.

Question 3 What happens when two south poles of magnets are placed together? A) they repel each other B) they attract each other C) they cancel each other out D) the strength of the magnet is doubled

Question 4 Ancient people discovered magnetic rocks called lodestone. What did they use them for? A) to start fires B) compasses C) sculptures D) telephone receivers

Question 5 If two magnets were in this order: SN SN, they would: A) repel each other B) attract each other C) do nothing D) none of the above

Question 6 You can tell if an object is magnetic if the grouping of atoms: A) Are scattered in all different directions. B) Are lined up in the same direction. C) Are lined up in opposite directions. D) Are half lined up and half scattered.

Question 7 How can you make a magnet lose its magnetism? A) by heating it B) by blowing on it C) by hitting it very hard D) both A and C

Question 8 A current carrying coil with many loops is called a(n) _________________.

Question 9 If you add more coils to a solenoid or increase the current, what happens to the strength of an electromagnet?

Question 10 The flow of charges through a material is called _________________.

Question 11 How many days of school are left? (Don’t count today, holidays, or Saturdays or Sundays)

Question 12 A material through which charge can flow easily is known as a(n) __________________.

Question 13 A complete path through which electric charges can flow is known as a(n) ________________.

Question 14 What subatomic particle in an atom gives it a magnetic field?

Question 15 What is the name of the device that has a magnetized needle that can spin freely?

Question 16 An electric generator converts ____________ energy into ___________ energy.

Question 17 A transformer increases or decreases A) energy B) resistance C) voltage D) direct current

Question 18 What happens to the poles when you break a bar magnet in half?

Question 19 True or False: Moving a magnet relative to a coil of wire induces a current in the wire if the coil is part of a complete circuit.

Question 20 Nickel is considered a(n) _________________ material because it contains magnetic domains.

Question 21 A solenoid with a ferromagnetic core is called a(n) ___________________.

Question 22 This is the area that is influenced by the Earth’s magnetic field.

Question 23 This is a device with fanlike blades that converts energy from various sources to electrical energy.

Question 24 Name two types of generators.

Question 25 An electronic device contains a transformer. Its primary coil has 200 turns, and its secondary coil has 20 turns. If the device is plugged into a 120-volt line, what is the output voltage of the device? Secondary coil turns = output voltage Primary coil turns input voltage

Question 26 This device is used by doctors to create more detailed images of the human body than are possible with X-rays.

Question 27 What day is your final exam on for your class?

Question 28 What type of magnet keeps its magnetism for a long time?

Question 29 A magnet’s field lines always start near the magnet’s ____________ pole.

Question 30 Electromagnetic devices like an electric motor convert ___________ energy into ____________ energy.

Question 31 What causes a ferromagnetic material to become magnetic? A) unpaired electrons B) paired electrons C) unpaired protons D) paired protons

Question 32 A galvanometer is a device used to measure ________________.

Question 33 True or False: In an alternating current produced by an AC generator, the flow of direction of charges switches back and forth.

Question 34 A charge moving in a magnetic field will be deflected in a direction that is ____________ to both the magnetic field and to the velocity of the charge.

Question 35 A ____________ transformer decreases the voltage so that it can enter homes safely.

Answer Key 1. C 13. circuit 25. 12 volts 2. D 14. electron 26. MRI 15. compass 27. day varies w/ class hour 4. B 16. mechanical, electrical 28. permanent 5. B 17. C 29. north 6. B 18. each magnet has a N & S pole 30. electrical, mechanical 7. D 31. A 19. True 8. solenoid 32. current 20. ferromagnetic 9. increases strength 33. True 21. electromagnet 10. current 34. perpendicular 22. magnetosphere 11. 11 days 35. step-down 23. turbine 12. conductor 24. AC and DC generators