Akwai nau'ikan canja wurin zafi guda uku ko canja wurin zafi , waɗanda suka haɗa da canja wurin zafi ta hanyar watsawa, convection, da radiation.
Canja wurin zafi ta hanyar watsawa. Lokacin da wani abu mai zafin jiki mai yawa ya haɗu da wani abu mai ƙarancin zafin jiki, kuzari yana motsawa daga abu mai zafin jiki mai yawa zuwa abu mai ƙarancin zafin jiki. Ƙarin kuzarin yana sa atom da ƙwayoyin da suka samar da abu su yi sauri. Yayin da suke motsawa, ƙwayoyin suna da kuzarin motsi (EK = ½ mv 2 ). Kwayoyin da ke motsawa da sauri (tare da ƙarin kuzarin motsi) suna karo da ƙwayoyin da ke kusa da su. Waɗannan ƙwayoyin sannan su yi karo da wasu ƙwayoyin da ke kusa da su. Da sauransu. Don haka ƙwayoyin suna karo da juna, suna canja wurin kuzari. Canja wurin zafi da ke faruwa ta hanyar karo tsakanin ƙwayoyin da suka samar da abu ana kiransa conduction. Conduction yawanci yana faruwa a cikin daskararru ko daga daskararru zuwa ruwa (ruwa zuwa daskararru) ko daga daskararru zuwa iskar gas (gas zuwa daskararru).
Canja wurin zafi ta hanyar convection. Convection yawanci yana faruwa ne a cikin ruwa (misali, ruwa) da iskar gas (misali, iska). Convection shine canja wurin zafi tare da motsi na abu saboda canje-canje a cikin yawansa. Yawan abu yana canzawa saboda girmansa yana canzawa. Girman abu yana canzawa saboda abin yana shan wani adadin zafi.
Canja wurin zafi ta hanyar radiation. Radiation shine canja wurin zafi ta hanyar amfani da raƙuman lantarki. Misalan radiation sun haɗa da ɗumin da jikinka ke ji lokacin da kake kusa da murhu da kuma hasken rana daga rana zuwa ƙasa. Rana tana da zafi mafi girma (kimanin Kelvin 6000), yayin da ƙasa ke da ƙaramin zafin jiki. Wannan bambancin zafin da ke tsakanin rana da ƙasa yana sa zafi ya motsa daga rana (zafi mafi girma) zuwa ƙasa (zafi mafi ƙanƙanta). Idan hasken rana zuwa ƙasa yana buƙatar matsakaici, kamar watsawa da watsawa, zafi ba zai isa ƙasa ba saboda dole ne ya ratsa ta cikin injin.
Misalin matsalolin
1. 2015/2016 Jarrabawar Ƙasa ta SMA/MA Physics Tambaya Mai Lamba 19
An haɗa sandunan ƙarfe masu girman iri ɗaya, amma an yi su da ƙarfe daban-daban, kamar yadda aka nuna a cikin hoton da ke ƙasa. Idan ƙarfin wutar lantarki na ƙarfe I ya ninka ƙarfin wutar lantarki na ƙarfe II sau 4, to zafin da ke mahadar ƙarfe biyu zai kasance…
A. 45oC
B. 40 o C
C. 35 o C
D. 30 o C
E. 25 o C
Tattaunawa
An san cewa:
Matsakaicin ƙarfin zafi na ƙarfe I = 4k
Maido da yanayin zafi na ƙarfe II = k
Zafin ƙarfe I = 50 oC
Zafin ƙarfe na gefen II = 0 oC
Tambaya: Zafin jiki a mahaɗar ƙarfe biyu
Amsa:
Tsarin da ake amfani da shi wajen canja wurin zafi ta hanyar amfani da na'urar sadarwa:
Bayani: Q/t = ƙimar canja wurin zafi, k = ƙarfin watsa zafi, A = yankin saman, T 1 -T 2 = canjin zafin jiki, l = tsawon sandar
Karfe biyu girmansu iri ɗaya ne don haka an cire A da l daga lissafin.
Amsar da ta dace ita ce B.
2. 2015/2016 Jarrabawar Ƙasa ta SMA/MA Physics Tambaya Mai Lamba 19
Hoton da ke ƙasa yana nuna sandunan ƙarfe na A da B na nau'ikan da aka haɗa a gefe ɗaya.
Yankin giciye na sandunan biyu iri ɗaya ne, amma tsawon A ya ninka tsawon B sau biyu kuma ma'aunin watsa zafi na A ya ninka na B sau 3. Idan ƙarshen A da B suna fuskantar yanayin zafi daban-daban, to ainihin zafin da ke wurin haɗuwa shine…
A. 60oC
B. 64 o C
C. 70 o C
D. 76 o C
E. 78 o C
Tattaunawa
An san cewa:
Tsarin juyar da zafi na sandar A = 3k
Maida wutar lantarki ta sandar B = k
Tsawon sandar A = 2l
Tsawon sandar B = l
Zafin gefen sandar A = 100 oC
Zafin gefen sandar B = 40 oC
Tambaya: Zafin jiki a haɗin sandunan biyu
Amsa:
Tsarin da ake amfani da shi wajen canja wurin zafi ta hanyar amfani da na'urar sadarwa:
Bayani: Q/t = ƙimar canja wurin zafi, k = ƙarfin watsa zafi, A = yankin saman, T 1 -T 2 = canjin zafin jiki, l = tsawon sandar
Duk sandunan suna da yanki ɗaya na giciye don haka an cire A daga lissafin.
Amsar da ta dace ita ce D.
3. 2014/2015 Jarrabawar Ƙasa ta SMA/MA Physics Tambaya Mai Lamba 14
Kula da wannan bayanin:
(1) ƙarfin lantarki na ƙarfe
(2) bambancin zafin jiki tsakanin ƙarshen ƙarfe
(3) tsawon ƙarfe
(4) nauyin ƙarfe
Abubuwan da ke ƙayyade yawan yaɗuwar zafi a cikin ƙarfe sune….
A. (1), (2), da (3)
B. (1) da (4)
C. (2) da (4)
D. (3) da (4)
E. (4) kawai
Tattaunawa
Canja wurin zafi a cikin ƙarfe shine canja wurin zafi ta hanyar sadarwa. Tsarin da ake amfani da shi don ƙimar canja wurin zafi ta hanyar sadarwa shine:
Bayani: Q/t = ƙimar canja wurin zafi, k = ƙarfin watsa zafi, A = yankin saman, T 1 -T 2 = canjin zafin jiki, l = tsawon sandar
Amsar da ta dace ita ce A.
