Zitsanzo za Mafunso Okhudza Mphamvu ya Maginito
Mphamvu ya maginito ndi imodzi mwa mphamvu zinayi zofunika kwambiri mu fizikisi ndipo imagwira ntchito yofunika kwambiri pazochitika zosiyanasiyana zachilengedwe ndi ukadaulo wamakono. Kumvetsetsa lingaliro ili kumafuna kumvetsetsa mozama za maginito, mphamvu ya maginito, malamulo a maginito amagetsi, ndi momwe amagwiritsidwira ntchito pa moyo watsiku ndi tsiku. Nkhaniyi ikambirana zitsanzo zingapo za mavuto okhudzana ndi mphamvu ya maginito, pamodzi ndi zokambirana zatsatanetsatane kuti zithandize owerenga kumvetsetsa bwino lingaliroli.
Kumvetsetsa Mphamvu ya Maginito
Musanakambirane za vutoli, ndikofunikira kumvetsetsa mfundo zoyambira za mphamvu ya maginito. Mphamvu ya maginito ndi mphamvu yopangidwa ndi mphamvu ya maginito ndipo imagwira ntchito pa tinthu tomwe timayendetsedwa ndi magetsi kapena zinthu zamaginito. Mphamvu ya maginito yokha ndi malo omwe mphamvu ya maginito imatha kumveka. Munthu amatha kumva mphamvu ya maginito pamene maginito awiri agwirizanitsidwa kapena pamene chinthu choyendetsedwa ndi magetsi chayikidwa mu mphamvu ya maginito.
Mphamvu ya maginito imasonyezedwa ndi mizere ya maginito yomwe imatuluka kuchokera kumpoto ndikulowa mu pole yakumwera. Kuphatikiza apo, mizati ya maginito yoyandikana nayo yokhala ndi mizati yotsutsana imakokana, pomwe mizati yofanana imakokana.
Mafunso ndi Kukambirana Zitsanzo
Funso 1: Mphamvu ya Maginito Yozungulira Waya Wowongoka
Waya wautali wowongoka umanyamula mphamvu ya 5 A. Dziwani kukula kwa mphamvu ya maginito pamtunda wa 0,2 m kuchokera pa waya.
Kukambirana:
Kuti tipeze kukula kwa mphamvu ya maginito yozungulira waya wowongoka wonyamula magetsi, tingagwiritse ntchito lamulo la Biot-Savart, koma pankhaniyi n'kosavuta kugwiritsa ntchito lamulo la Ampere:
Mphamvu ya maginito \( B \) yozungulira waya wautali wowongoka ikhoza kuwerengedwa pogwiritsa ntchito fomula iyi:
\[ B = \frac{\mu_0 I}{2\pi r} \]
Kumene:
– \( \mu_0 \) ndi vacuum permeability (\( 4\pi \times 10^{-7} \, T \cdot m/A \))
– \( I \) ndi mphamvu yamagetsi (A)
– \( r \) ndi mtunda wochokera ku waya (m)
Ndi mfundo zomwe zaperekedwa:
– \( Ine = 5 \, A \)
– \( r = 0,2 \, m \)
Sinthani mfundo izi mu fomula iyi:
\[
B = \frac{4\pi \nthawi 10^{-7} \nthawi 5}{2\pi \nthawi 0,2}
\]
Chepetsani:
\[
B = \frac{4\pi \nthawi 10^{-7} \nthawi 5}{2\pi \nthawi 0,2} \mzere wolunjika
B = \frac{4 \times 5 \times 10^{-7}}{2 \times 0,2} \rightarrow
B = \frac{20 \times 10^{-7}}{0,4} = 5 \times 10^{-6} \, T \] kapena \(5 \, \mu T\) (microtesla).
Funso 2: Mphamvu ya Lorentz pa Tinthu Tomwe Tili ndi Mphamvu
Tinthu tating'onoting'ono tomwe tili ndi mphamvu yabwino \(q = 1 \, \mu C\) (microCoulomb) tikuyenda ndi liwiro \(v = 2 \times 10^4 \, m/s\) timalowa mu mphamvu ya maginito yofanana ndi kulowetsedwa kwa maginito \(B = 0,5 \, T\) molunjika ku mbali ya liwiro la tinthu. Werengani mphamvu ya maginito yomwe tinthu tating'onoting'ono timaipeza.
Kukambirana:
Mphamvu ya maginito (mphamvu ya Lorentz) yomwe imawonedwa ndi tinthu tomwe timayatsidwa imatha kuwerengedwa pogwiritsa ntchito njira iyi:
\[ F = q \cdot v \cdot B \cdot \sin(\theta) \]
Kumene:
– \( q \) ndi mphamvu yamagetsi (C)
– \( v \) ndi liwiro la tinthu tating'onoting'ono (m/s)
– \( B \) ndi mphamvu ya maginito (T)
– \( \theta \) ndi ngodya pakati pa liwiro ndi malangizo a mphamvu yamaginito
Pankhaniyi, mphamvu ya maginito imakhala yolunjika ku liwiro la tinthu tating'onoting'ono, kotero kuti
\(\theta = 90^\circ\) ndi \(\sin(90^\circ) = 1\).
Zoperekedwa:
– \( q = 1 \, \mu C = 1 \nthawi 10^{-6} \, C \)
– \( v = 2 \nthawi 10^4 \, m/s \)
– \( B = 0,5 \, T \)
Sinthani mfundo izi mu fomula iyi:
\[
F = 1 \nthawi 10^{-6} \cdot 2 \nthawi 10^4 \cdot 0,5 \cdot 1 \]
Chepetsani:
\[
F = 1 \nthawi 10^{-6} \nthawi 10^4 \nthawi 1 = 10^{-6} \nthawi 0,5 = 10^{-6} \nthawi 0,5 = 1 \nthawi 10^{-6} \nthawi 0.5 = 1 \nthawi 10^{-6} \, N
\]
Funso 3: Mphamvu ya Maginito Pakati pa Chizunguliro cha Waya
Antena yozungulira (lupu) yokhala ndi utali wa masentimita 10 imaperekedwa ndi mphamvu ya 3 A. Kodi mphamvu ya maginito pakati pa bwalo ndi yotani?
Kukambirana:
Mphamvu ya maginito pakati pa kuzungulira kwa waya wonyamula magetsi imatha kuwerengedwa pogwiritsa ntchito njira iyi:
\[
B = \frac{\mu_0 I}{2r}
\]
Kumene:
– \( \mu_0 \) ndi vacuum permeability (\( 4\pi \times 10^{-7} \, T \cdot m/A \))
– \( I \) ndi mphamvu yamagetsi (3 A)
– \( r \) ndi utali wozungulira (10 cm = 0,1 m)
Sinthani mfundo izi mu fomula iyi:
\[
B = \frac{4\pi \times 10^{-7} \times 3}{2 \times 0,1}
\]
Chepetsani:
\[
B = \frac{4\pi \nthawi 10^{-7} \nthawi 3}{0,2} = \frac{12\pi \nthawi 10^{-7}}{0,2} = 60 \nthawi 10^{-7} \, T \]
\[ B = 6 \times 10^{-6} \, T \] kapena \(6 \, \mu T\) (microtesla).
Mapeto
Kumvetsetsa mphamvu zamaginito n'kofunika kwambiri pa sayansi ya fizikisi ndi momwe imagwiritsidwira ntchito muukadaulo wamakono. Kudzera mu zitsanzo zomwe takambirana pamwambapa, titha kuwona momwe mfundo zazikulu monga mphamvu zamaginito, lamulo la Ampère, ndi mphamvu ya Lorentz zimagwiritsidwira ntchito m'mikhalidwe yeniyeni. Kuchita zinthu nthawi zonse kuthetsa mavuto ngati awa kudzakuthandizani kwambiri kumvetsetsa kwanu ndikukulitsa luso lanu mu sayansi ya fizikisi yamaginito.
Nkhaniyi ikuyembekezeka kupereka chithunzi chomveka bwino cha momwe mphamvu zamaginito zimagwirira ntchito komanso momwe tingafufuzire mavuto okhudzana ndi lingaliro ili mwatsatanetsatane.
