262 InductanceP32.79(a)BNI==×⋅=×−−µπ0734101 4002 001 202 9310ATmAAmT upwardejbgafbg...(b)uB==××⋅=⋅FHGIKJ==−−2032722 93102 4103 4213 423 42µπ....TT m AJ mN m1 JNmPa32ejejej(c)To produce a downward magnetic field, the surface of the superconductor must carry aclockwisecurrent.(d)The vertical component of the field of the solenoid exerts an inward force on thesuperconductor. The total horizontal force is zero. Over the top end of the solenoid, its fielddiverges and has a radially outward horizontal component. This component exerts upwardforce on the clockwise superconductor current. The total force on the core is upward. Youcan think of it as a force of repulsion between the solenoid with its north end pointing up,and the core, with its north end pointing down.(e)FPA==×LNMOQP=×−−3 421 10101 3010223...PamNafejπNote that we have not proven that energy density is pressure. In fact, it is not in some cases;Equation 21.2 shows that the pressure is two-thirds of the translational energy density in an
This is the end of the preview.
access the rest of the document.
Magnetic Field, Fundamental physics concepts, Energy density, 1.20 m, downward magnetic field, outward horizontal component