< BackNext >PreviewMain Electromagnetism Preview Chapter 18 CRCT Preparation

< BackNext >PreviewMain CRCT Preparation Chapter The table shows the number of primary and secondary coil loops in four transformers. Which of the four transformers decrease current? A A and C B B and C C B and D D A, B, C, and D

< BackNext >PreviewMain Chapter 18 CRCT Preparation 1. The table shows the number of primary and secondary coil loops in four transformers. Which of the four transformers decrease current? A A and C B B and C C B and D D A, B, C, and D

< BackNext >PreviewMain Chapter 18 CRCT Preparation 2. Which of the four transformers are step-down transformers? A A and C B B and C C B and D D A, B, C, and D

< BackNext >PreviewMain Chapter 18 CRCT Preparation 2. Which of the four transformers are step-down transformers? A A and C B B and C C B and D D A, B, C, and D

< BackNext >PreviewMain 3. In which of these locations would you find power lines with the highest voltage? A in a neighborhood B leaving a power distribution center C leaving a power plant D entering a house Chapter 18 CRCT Preparation

< BackNext >PreviewMain Chapter 18 CRCT Preparation 3. In which of these locations would you find power lines with the highest voltage? A in a neighborhood B leaving a power distribution center C leaving a power plant D entering a house

< BackNext >PreviewMain 4. An electromagnet used in a junkyard can only pick up cars. How could the electromagnet be improved so that it could lift trucks and other large vehicles? A The electric current and the number of coils in the solenoid could be increased. B The electric current could be increased and the number of coils in the solenoid could be decreased. C The electric current and the number of coils in the solenoid could be decreased. D The electric current could be decreased and the number of coils in the solenoid could be increased. Chapter 18 CRCT Preparation

< BackNext >PreviewMain Chapter 18 CRCT Preparation 4. An electromagnet used in a junkyard can only pick up cars. How could the electromagnet be improved so that it could lift trucks and other large vehicles? A The electric current and the number of coils in the solenoid could be increased. B The electric current could be increased and the number of coils in the solenoid could be decreased. C The electric current and the number of coils in the solenoid could be decreased. D The electric current could be decreased and the number of coils in the solenoid could be increased.

< BackNext >PreviewMain Chapter 18 CRCT Preparation 5. Catherine rubs an iron nail in one direction with the south pole of a magnet. Which of the following is true of the magnetized nail? A It will only be attracted to the north pole of a bar magnet. B It has a strong north pole and a much weaker south pole. C Its domains have become rearranged so that they line up in one direction. D The bar magnet has caused a random arrangement of the nail’s domains.

< BackNext >PreviewMain Chapter 18 CRCT Preparation 5. Catherine rubs an iron nail in one direction with the south pole of a magnet. Which of the following is true of the magnetized nail? A It will only be attracted to the north pole of a bar magnet. B It has a strong north pole and a much weaker south pole. C Its domains have become rearranged so that they line up in one direction. D The bar magnet has caused a random arrangement of the nail’s domains.

< BackNext >PreviewMain 6. An electric outlet in the United States provides 120 volts of alternating current. An electric outlet in England provides 230 volts of alternating current. What kind of device would you need in order to use your hair dryer in a hotel in England? A a galvanometer B a solenoid C a commutator D a step-down transformer Chapter 18 CRCT Preparation

< BackNext >PreviewMain Chapter 18 CRCT Preparation 6. An electric outlet in the United States provides 120 volts of alternating current. An electric outlet in England provides 230 volts of alternating current. What kind of device would you need in order to use your hair dryer in a hotel in England? A a galvanometer B a solenoid C a commutator D a step-down transformer

< BackNext >PreviewMain 7. When a current-carrying wire is placed between two poles of a magnet, the wire jumps up, as shown in the diagram. Which of the following statements about this phenomenon is true? Chapter 18 CRCT Preparation C The battery transfers its magnetic field to the wire. D The wire causes the domains of the magnet to rearrange. A The wire creates a magnetic field that interacts with the magnetic field of the magnet. B The north pole of the magnet interacts with the south pole of the wire.

< BackNext >PreviewMain 7. When a current-carrying wire is placed between two poles of a magnet, the wire jumps up, as shown in the diagram. Which of the following statements about this phenomenon is true? Chapter 18 CRCT Preparation C The battery transfers its magnetic field to the wire. D The wire causes the domains of the magnet to rearrange. A The wire creates a magnetic field that interacts with the magnetic field of the magnet. B The north pole of the magnet interacts with the south pole of the wire.

< BackNext >PreviewMain 8. Jane puts the north pole of a bar magnet near an object on her desk. As the magnet gets closer to the object, the object is repelled and moves away from the magnet. Which of the following statements about the object on Jane’s desk is true? A The object has a north pole but no south pole. B The object is a magnet or has been magnetized. C The object has randomly-arranged domains. D The object is not made of metal. Chapter 18 CRCT Preparation

< BackNext >PreviewMain Chapter 18 CRCT Preparation 8. Jane puts the north pole of a bar magnet near an object on her desk. As the magnet gets closer to the object, the object is repelled and moves away from the magnet. Which of the following statements about the object on Jane’s desk is true? A The object has a north pole but no south pole. B The object is a magnet or has been magnetized. C The object has randomly-arranged domains. D The object is not made of metal.

< BackNext >PreviewMain 9. Elise tells her friends that Earth’s magnetic field is created by a giant bar magnet at Earth’s center. Is she right? Explain your answer. Chapter 18 CRCT Preparation

< BackNext >PreviewMain 9. Answer – Although Earth does act like a giant bar magnet, the temperature of Earth’s core is too high to maintain aligned domains. As Earth rotates, the magnetic field is generated by electric charges that move within Earth’s core. Chapter 18 CRCT Preparation

< BackNext >PreviewMain 10. Dennis is building a toy car. He is trying to decide whether to install an electric generator or an electric motor to power the toy. Which should he choose? Explain your answer. Chapter 18 CRCT Preparation

< BackNext >PreviewMain 10. Answer – Dennis should install the electric motor. Electric motors convert electrical energy into mechanical energy that is required to make the car move. Electric generators convert mechanical energy into electrical energy, which would not be useful in the toy. Chapter 18 CRCT Preparation