North Pole vs South Pole
North Pole thiab South Ncej yog ob lub ntsiab lus tseem ceeb hauv cov hlau nplaum. Cov ntsiab lus no muaj txiaj ntsig zoo heev thaum nws los txog rau thaj chaw xws li navigation, physics, electromagnetic theory, hluav taws xob engineering, hluav taws xob tsim hluav taws xob thiab ntau yam haujlwm. Nws yog qhov yuav tsum tau muaj kev nkag siab meej hauv cov ntsiab lus no thiaj li ua tau zoo hauv cov haujlwm no. Hauv tsab xov xwm no, peb yuav tham txog dab tsi hlau nplaum yog dab tsi, North Ncej thiab South Ncej yog dab tsi, lawv cov lus txhais, yog tias muaj, lawv qhov zoo sib xws thiab thaum kawg qhov txawv ntawm North Ncej thiab South Ncej.
Yuav kom nkag siab tias North Ncej thiab South Ncej yog dab tsi, lub tswvyim ntawm magnetic flux (magnetic field lines) yuav tsum tau.
Magnetic Flux yog dab tsi?
Magnets tau tshawb pom los ntawm Suav thiab Greeks nyob rau lub sijhawm 800 BC. mus txog 600 B. C. Xyoo 1820, Hand Christian Oersted, tus kws kho mob Danish tau tshawb pom tias cov hlau nqa tam sim no ua rau lub koob koob mus rau sab xis ntawm cov hlau. Qhov no yog hu ua induction magnetic teb. Ib qho chaw sib nqus yog ib txwm tshwm sim los ntawm kev txav mus los. (piv txwv li lub sijhawm sib txawv hluav taws xob). Cov hlau nplaum tas mus li yog qhov tshwm sim ntawm electron spin ntawm atoms sib txuas ua ke los tsim cov net magnetic teb. Yuav kom nkag siab txog lub tswvyim ntawm magnetic flux ib tug yuav tsum xub to taub lub tswvyim ntawm magnetic teb kab. Cov kab hlau nplaum sib nqus lossis cov kab sib nqus ntawm lub zog yog ib txheej ntawm cov kab kev xav, uas tau kos los ntawm N (sab qaum teb) ncej ntawm cov hlau nplaum mus rau S (sab qab teb) ncej ntawm cov hlau nplaum. Hauv kev txhais, cov kab no yeej tsis hla ib leeg tshwj tsis yog qhov sib nqus qhov sib nqus yog xoom. Nws yuav tsum raug sau tseg tias cov kab sib nqus ntawm lub zog yog lub tswv yim. Lawv tsis muaj nyob hauv lub neej tiag tiag. Nws yog ib qho qauv, uas yog yooj yim los sib piv cov magnetic teb qualitatively. Qhov sib nqus flux nyob rau saum npoo yog hais tias yog proportional rau tus naj npawb ntawm cov kab sib nqus ntawm cov quab yuam perpendicular mus rau qhov chaw muab. Txoj cai Gauss, txoj cai Ampere thiab Biot-Savart txoj cai yog peb txoj cai tseem ceeb tshaj plaws thaum xam cov sib nqus flux saum npoo. Nws tuaj yeem ua pov thawj tias net magnetic flux tshaj qhov chaw kaw yog ib txwm xoom siv Gauss txoj cai. Qhov no tseem ceeb heev vim qhov no qhia tau hais tias cov hlau nplaum ib txwm tshwm sim hauv khub. Sib nqus monopoles tsis tuaj yeem pom. Qhov no kuj qhia tau hais tias txhua kab magnetic teb yuav tsum tau txiav. Qhov sib nqus flux ntom ntom ntawm cov hlau nplaum yog qhov siab tshaj plaws ntawm North Ncej thiab South Ncej.
Dab tsi yog qhov txawv ntawm North Pole thiab South Pole?
• North Ncej yog qhov chaw uas cov kab hlau nplaum pib. Cov no yog cov txheej txheem kev xav, uas muaj txiaj ntsig zoo rau kev soj ntsuam zoo ntawm thaj chaw. Raws li Fleming txoj cai, North Ncej tuaj yeem txiav txim siab siv txoj cai corkscrew sab xis. A North Ncej ib txwm tawm tsam North Ncej thiab nyiam South Ncej.
• South Ncej yog qhov chaw uas cov kab hlau nplaum xaus. Qhov no kuj tuaj yeem txiav txim siab siv Fleming txoj cai.
