E Lauren''s Kindle for PC - Physics: A Conceptual World View (Available 2010 Titles Enhanced Web Assign) File View Go Tools Help g xx Library Show Notebook T5. In the following figure, you are looking at the end of @ Tield Tet, Tight, up, down, into the page, or out of the Table of Contents long straight wire. The current in the wire is directed out page? Explain. of the page. At the point labeled A, is the direction of the magnetic field left, right, up, down, into the page, or out ~ 5 5y > : of the page? What is the direction at point B2 Explain. Q Conceptual Questions Peg E P A O B 1 1 A B E:l Exercises I (out of page) v 16. Along straight wire carries a current in the direction = Ch 22: Electromagnetism shown in the following figure. At the point labeled A, is O the direction of the magnetic field left, right, up, down, o - . e . i Two wires carry current into the page, as shown in the fol- into the page, or out of the page? What is the direction of 3 % 5 . Magnets 2 S : lowing figure. One wire carries a current , and the other the magnetic field at the point labeled B? Explain. | carries a current 21, Which of the arrows best represents the direction of the magnetic field at point A, which is Electric Currents and Magnetism 1 the same distance from both wires? Explain. A B 21 Making Magnets The Ampere The Magnetic Earth 17. The following figure shows the top view of a compass next to a long straight wire. An arrow indicates the north pole of the compass. When a switch is closed, a current is Charged Particles in Magnetic Fields established in the wire, and the compass needle initially rotates as indicated. Is the direction of the current in the 2 g wire int the page or out:of fhe page? Explain 23, In Melville's Moby Dick, Captain Ahab regained the con- Magnetism and Electric Currents fidence of his crew when he fixed the compass that had Top view been damaged by an electrical storm so that it pointed w north. How might he have done this? Transformers o> O Current-carrying 24. Lodestone (magnetite) is an igneous rock, one that forms N wire from molten material. How do you suppose it became magnetized? Generators and Motors 18. The following figure shows the top view of a compass 55 i Fiib vowexpect il fappento fhesivendidite next to a long straight wire. The north pole of the com- 2 g et R pass is indicated by an arrow. When a switch is closed, the [T\"g'fc\""\" ofabar magnet that s dropped on a har A Question of Symmetry currentis directed out of the page as indicated. Will the oor? compass needle initially rotate clockwise or counterclock- ~ 26. Would you expect the head of a steel hammer to be mag- wise? Explain. netized? Explain. Electromagnetic Waves . . . . Top view 27. Two long straight wires carry currents in opposite direc- tions. The current in wire 1 is twice the current in wire Radio and TV @ ) 2. If the net magnetic force per unit length on wire 1 is op Current carried 4 newtons per meter, what is the net magnetic force per out of the page unit length on wire 2? Summary 19. In electric circuits and telephone lines, two wires carrying ~ 28. Three long straight wires each carry identical current in vaents b apposits direciing are tristed iogether How the directions shown in the following figure. What is the does this reduce the magnetic fields surrounding the direction of the net force on the wire at the right? Key Terms e wires? 20. Can you use a compass to locate the electric wires located Conceptual Questions inside the walls of your house? Explain. 21. Two long straight wires carry identical currents in oppo- site directions, as shown in the following figure. At the Exercises v points labeled A and B, is the direction of the magnetic 72% Page 490 of 693 - Location 12166 of 17106 Closed road on OH-4... 12:44 PM =] Leriplrz g