<p>Draw the magnetic field lines around a straight section of wire carrying a current horizontally to the left.</p>
<p>x x x x x x x x x x x x x
<----------------------- current
. . . . . . . . . . . . . . . . </p>
<p>Is this what the figure should look like? where "x" represents the current going into the page, and "." represents the current coming out of the page.</p>
<p>Thats what I get, using the right hand screw rule.</p>
<p>I am stuck on this one.</p>
<p>Suppose you have three iron rods, two of which are magnetized but the third is not. How would you determine which two are the magnets without using any additional objects?</p>
<p>Cant you distort them to find two ends that would repel eachother meaning that both of them would have to be magnetized. The normal one would always attract.</p>
<ol>
<li>What is the maximum current that a wire can carry if an experimenter is performing an experiement 1.0 m away that deals with the Earth's magnetic field, which she wishes to measure to +/- 1 percent?</li>
</ol>
<p>I keep getting 277 A for the current. But my book says its 3A?!?!!?</p>
<p>Does anyone know? I keep getting 277.75... I hate this.</p>