Mohlala oa Lipotso tsa Puisano mabapi le Mefuta ea Khanyetso
Ho hanyetsa ke mohopolo oa motheo ho electromagnetism le karolo ea bohlokoa ea thuto ea fisiks, haholo-holo lipotolohong tsa motlakase. Sehlooho sena se tla tšohla mehlala e 'maloa ea mathata a ho hanyetsa, e felletseng ka litlhaloso le litharollo.
Mofuta oa Thibelo ke Eng?
Resistivity (\(\rho\)) ke tekanyo ya thepa ya thepa e etsang qeto ya hore na e sitisa phallo ya motlakase hakae. Resistivity e lekanngwa ka di-ohm-meter (Ω·m). Ha resistivity ya thepa e phahame, ho ba thata le ho feta hore motlakase o phalle ka yona.
Foromo ea motheo ea ho bala khanyetso (\(R\)) ho mokhanni ea nang le bolelele (\(L\)) le sebaka se tšekaletseng (\(A\)) ke:
\[ R = \rho \frac{L}{A} \]
Lipotso tsa Mehlala le Puisano
Mohlala oa Potso ea 1:
Ha ho fanoe ka terata ea koporo e bolelele ba limithara tse 2 le sebaka se tšekaletseng sa 0,5 mm\(^2\). Khanyetso e khethehileng ea koporo ke \(1.68 \times 10^{-8} \; \Omega \cdot m\). Bala khanyetso ea terata.
Puisano:
1. Fetola sebaka se tšekaletseng ho tloha ho mm\(^2\) ho ea ho m\(^2\):
\[ 0.5 \; \mongolo{mm}^2 = 0.5 \makgetlo a 10^{-6} \; \mongolo{m}^2 \]
2. Sebelisa foromo \( R = \rho \frac{L}{A} \):
\[ R = (1.68 \makgetlo a 10^{-8}) \frac{2}{0.5 \makgetlo a 10^{-6}} \]
\[ R = (1.68 \makgetlo a 10^{-8}) \makgetlo (4 \makgetlo a 10^{6}) \]
\[ R = 6.72 \makgetlo a 10^{-2} \; \Omega\]
Kahoo, khanyetso ea terata ea koporo ke 0.0672 Ω.
Mohlala oa Potso ea 2:
Terata ea aluminium e na le khanyetso ea \(2.82 \makhetlo a 10^{-8} \; \Omega \cdot m\). Haeba bolelele ba terata e le limithara tse 10 'me e na le khanyetso ea 0.0564 Ω, sebaka sa terata se tšekaletseng ke sefe?
Puisano:
1. Hoa tsebahala:
– Khanyetso e itseng, \(\rho = 2.82 \times 10^{-8} \; \Omega \cdot m\)
– Bolelele, \( L = 10 \; \text{m} \)
– Khanyetso \( R = 0.0564 \; \Omega \)
2. Sebelisa foromo \( R = \rho \frac{L}{A} \) ho fumana sebaka se nang le karolo e tšekaletseng:
\[ R = \rho \frac{L}{A} \]
\[ 0.0564 = 2.82 \makgetlo a 10^{-8} \frac{10}{A} \]
\[ 0.0564 = 2.82 \makgetlo a 10^{-7} \frac{1}{A} \]
\[ A = \frac{2.82 \makgetlo a 10^{-7}}{0.0564} \]
\[ A = 5 \makgetlo a 10^{-6} \; \mongolo{m}^2 \]
Kahoo, sebaka se tšekaletseng sa terata ea aluminium ke \(5 \times 10^{-6} \; \text{m}^2\).
Mohlala oa Potso ea 3:
Ho thoe'ng haeba re hokahanya lithapo tse peli tse fapaneng tsa conductor ka tatellano le ka tsela e ts'oanang, phello ke efe khanyetsong eohle le mokhoa oa ho e bala? A re re re na le terata ea koporo le terata ea aluminium, e 'ngoe le e 'ngoe e bolelele ba limithara tse 5 le sebaka se tšekaletseng sa 1 mm\(^2\). Khanyetso e ikhethang ea koporo ke \(1.68 \times 10^{-8} \; \Omega \cdot m\) 'me aluminium ke \(2.82 \times 10^{-8} \; \Omega \cdot m\).
Puisano:
1. Bala khanyetso ea terata ka 'ngoe.
– Terata ea koporo:
\[ R_{\text{copper}} = \rho \frac{L}{A} = (1.68 \times 10^{-8}) \frac{5}{1 \times 10^{-6}} \]
\[ R_{\text{copper}} = 8.4 \makgetlo a 10^{-2} \; \Omega \]
– Terata ea aluminium:
\[ R_{\text{aluminium}} = \rho \frac{L}{A} = (2.82 \times 10^{-8}) \frac{5}{1 \times 10^{-6}} \]
\[ R_{\text{aluminium}} = 1.41 \makgetlo a 10^{-1} \; \Omega\]
2. Haeba e hokahantsoe ka letoto:
\[ R_{\text{total}} = R_{\text{copper}} + R_{\text{aluminium}} \]
\[ R_{\text{total}} = 8.4 \times 10^{-2} + 1.41 \times 10^{-1} \]
\[ R_{\text{total}} = 0.224 \; \Omega\]
3. Haeba e hokahantsoe ka ho bapa:
\[ \frac{1}{R_{\text{total}}} = \frac{1}{R_{\text{copper}}} + \frac{1}{R_{\text{aluminium}}} \]
\[ \frac{1}{R_{\text{total}}} = \frac{1}{8.4 \times 10^{-2}} + \frac{1}{1.41 \times 10^{-1}} \]
\[ \frac{1}{R_{\text{total}}} = \frac{1}{0.084} + \frac{1}{0.141} \]
\[ \frac{1}{R_{\text{total}}} = 11.905 + 7.092 \]
\[ \frac{1}{R_{\text{total}}} = 18.997 \]
\[ R_{\text{total}} = \frac{1}{18.997} \]
\[ R_{\text{total}} \hoo e ka bang 0.0526 \; \Omega\]
Kahoo, khanyetso e felletseng ha lithapo tse peli li hokahantsoe ka tatellano ke 0.224 Ω 'me ha li hokahantsoe ka ho lekana ke 0.0526 Ω.
Qetello
Ho hanyetsa ha thepa ho bohlokoa haholo ho fumaneng khanyetso e felletseng ea mokhanni. Ka ho tseba ho hanyetsa, bolelele le sebaka se tšekaletseng, re ka bala khanyetso ea thepa re sebelisa mokhoa o bonolo. Mehlala e kaholimo e bontša hore ho utloisisa le ho bala khanyetso ho bapala karolo ea bohlokoa moralong le tlhahlobong ea lipotoloho tsa motlakase. Ka ho ikoetlisa, kutloisiso ea rona ea mohopolo oa khanyetso e tla teba le ho sebetsa maemong a fapaneng.
Ho hanyetsa le dipalopalo tse amanang le yona ke tsa bohlokwa bakeng sa ditshebediso tse ngata tse sebetsang boenjiniereng le fisiks. Ka hona, kutlwisiso e tiileng ya mohopolo ona e bohlokwa ho mang kapa mang ya amehang mafapheng ana.
