PHY 303L Lecture Notes - Niobium, Unit Vector, Superconductivity
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Rashid (sar3553) hw8 sources of magnetic field storr (37537) Multiple-choice questions may continue on the next column or page nd all choices before answering. Consider the left straight part of the wire. The line element d~s at this part, if we come in from , points towards o, i. e. , in the x- direction. We need to nd d~s r to use the. However, in this part of the wire, r is pointing towards o as well, so d~s and r are parallel meaning d~s r = 0 for this part of the wire. It is now easy to see that the right part, having a d~s antiparallel to r, also gives no contribution to ~b at o. Let us go through the semicircle c. the element d~s, which is along the wire, will now be perpendicular to r, which is pointing along the radius towards o. | d~s r| = ds using the fact that r is a unit vector.
