5 Piv txwv ntawm Cov Lus Nug Txog Kev Hloov Kub
1. Ob tug pas nrig P thiab Q uas loj ib yam tab sis muaj ntau hom hlau sib txawv raug txuas raws li pom hauv daim duab hauv qab no. Yog tias tus coefficient thermal conduction ntawm P yog ob npaug ntawm tus coefficient thermal conduction ntawm Q, ces qhov kub ntawm ciam teb ntawm P thiab Q yog...
A. 600 oC
B. 200 o C
C. 100 o C
D. 90 o C
E. 60 o C
Kev Sib Tham
Nws paub tias:
Ob tug pas nrig P thiab Q muaj tib qhov loj
Tus coefficient thermal conductivity P yog ob npaug ntawm tus coefficient thermal conductivity Q
Qhov kub ntawm qhov kawg ntawm tus pas nrig P yog 90 o , qhov kub ntawm qhov kawg ntawm tus pas nrig Q yog 0 o thiab qhov kub ntawm tus pas nrig P thiab Q yog T.
Lo lus nug: Qhov kub ntawm ciam teb P thiab Q
Lus teb:
Cov mis rau tus nqi ntawm kev hloov pauv cua sov los ntawm kev sib txuas lus :
Kev piav qhia: Q/t = tus nqi hloov cua sov, k = kev coj ua cua sov, A = thaj tsam hla, T 1 = kub siab, T 2 = kub qis, l = ntev ntawm yam khoom.
Ob tug pas nrig P thiab Q muaj tib qhov loj me yog li ntawd thaj chaw ntawm qhov chaw (A) thiab qhov ntev (l) ploj ntawm qhov sib npaug. Qhov sib npaug saum toj no hloov mus rau:
Tus coefficient ntawm thermal conduction P yog ob npaug ntawm tus coefficient ntawm thermal conduction Q. Cov kab zauv saum toj no hloov mus rau:
Qhov kub ntawm lub hau ntawm tus pas nrig P yog 90 o , qhov kub ntawm lub hau ntawm tus pas nrig Q yog 0 o thiab qhov kub ntawm cov pas nrig P thiab Q yog T. Cov kab zauv saum toj no hloov mus rau:
Qhov kub ntawm ciam teb P thiab Q yog 60 o C.
Cov lus teb yog yog E.
2. Cov pas nrig A thiab B muaj thaj tsam thiab ntev sib npaug. Yog tias tus coefficient conduction ntawm pas nrig A = 1/4 npaug ntawm tus coefficient conduction ntawm pas nrig B, ces ob qho tib si raug cua sov ntawm ib kawg thiab nws hloov tawm tias ob qho tib si muaj kev hloov pauv kub tib yam. Tom qab ntawd qhov piv ntawm tus nqi hloov pauv cua sov ntawm pas nrig A thiab pas nrig B yog…..
A. 1: 4
B. 1: 2
C. 1: 1
D. 2: 1
E. 4: 1
Kev Sib Tham
Nws paub tias:
Thaj tsam hla ntawm tus pas A (A) = thaj tsam hla ntawm tus pas B (A)
Qhov ntev ntawm tus pas A (l) = qhov ntev ntawm tus pas B (l)
Tus coefficient ntawm kev sib txuas ntawm tus pas A (k) = 1/4 npaug ntawm tus coefficient ntawm kev sib txuas ntawm tus pas B (1/4 k)
Kev hloov pauv ntawm qhov kub ntawm bar A (ΔT) = kev hloov pauv ntawm qhov kub ntawm bar B (ΔT)
Xav tau: Kev sib piv ntawm qhov ceev hloov pauv cua sov ntawm pas nrig A thiab pas nrig B
Lus teb:
Cov mis rau tus nqi ntawm kev hloov pauv cua sov los ntawm kev sib txuas lus:
Kev piav qhia: Q/t = tus nqi hloov cua sov, k = kev coj ua cua sov, A = thaj tsam hla, T 2 = kub siab, T 1 = kub qis, l = ntev ntawm yam khoom.
Thaj tsam hla ntu yog tib yam, qhov ntev ntawm tus pas nrig yog tib yam, qhov hloov pauv kub yog tib yam.
Cov lus teb yog yog E.
3. Ob tug pas hlau A thiab B uas loj ib yam muaj tus coefficient conduction ntawm 2k thiab k.
Ob qho tib si txuas ua ke thiab cov qhov kawg dawb raug rau qhov kub raws li pom hauv daim duab.
Qhov kub (T) ntawm qhov sib koom ua ke hlau A thiab B yog ...
A. 80 o C
B. 100 o C
C. 120 o C
D. 150 o C
E. 160 o C
Kev Sib Tham
Nws paub tias:
Ob tug pas hlau A thiab B muaj tib qhov loj
Tus coefficient conduction ntawm hlau A = 2k
Cov coefficient ntawm kev sib kis hlau B = k
Kub ntawm lub hau hlau A = 210 o C
Kub ntawm lub hau hlau B = 30 o C
Xav tau: Kub (T) ntawm cov hlau sib txuas A thiab B
Lus teb:
Cov mis rau tus nqi ntawm kev hloov pauv cua sov los ntawm kev sib txuas lus :
Kev piav qhia: Q/t = tus nqi hloov cua sov, k = kev coj ua cua sov, A = thaj chaw saum npoo, T 1 -T 2 = kev hloov kub, l = qhov ntev ntawm tus pas nrig
Ob tug pas hlau A thiab B muaj tib qhov loj me yog li ntawd thaj tsam ntawm qhov chaw (A) thiab qhov ntev (l) ntawm cov pas hlau raug tshem tawm ntawm qhov sib npaug.
Cov lus teb yog D.
4. Ob tug pas hlau uas muaj tib qhov ntev thiab thaj tsam hla tau txuas ua ke raws li pom hauv daim duab hauv qab no. Cov coefficient thermal conduction ntawm tus pas hlau thib ob = 2 npaug ntawm cov coefficient thermal conduction ntawm tus pas thawj. Yog tias tus pas thawj raug cua sov kom T 1 = 100 o C thiab T 2 = 25 o C, ces qhov kub ntawm qhov sib koom ua ke (T) yog ...
A. 30 oC
B. 35 o C
C. 40 o C
D. 45 o C
E. 50 o C
Kev Sib Tham
Nws paub tias:
Ob tug pas hlau A thiab B muaj tib qhov loj
Cov coefficient ntawm kev sib txuas ntawm tus pas nrig I = k
Cov coefficient ntawm kev sib kis ntawm tus pas nrig II = 2k
Kub ntawm lub hau ntawm tus pas nrig I = 100 o C
Kub ntawm lub taub hau pas nrig II = 25 o C
Nug: Kub ntawm cov pob qij txha ntawm cov pas nrig I thiab II
Lus teb:
Cov mis rau tus nqi ntawm kev hloov pauv cua sov los ntawm kev sib txuas lus:
Kev piav qhia: Q/t = tus nqi hloov cua sov, k = kev coj ua cua sov, A = thaj chaw saum npoo, T 1 -T 2 = kev hloov kub, l = qhov ntev ntawm tus pas nrig
Ob tug pas hlau A thiab B muaj tib qhov loj me yog li ntawd thaj tsam ntawm qhov chaw (A) thiab qhov ntev (l) ntawm cov pas hlau raug tshem tawm ntawm qhov sib npaug.
Cov lus teb yog C.
5. Peb tug pas hlau sib txawv A, B thiab C tab sis muaj tib qhov ntev thiab thaj tsam hla, txuas nrog ib leeg raws li pom hauv daim duab hauv qab no.
Kev coj ua hluav taws xob loj 4 kA = 2 kB = kC thiab T1 = 100oC thiab T4 = 20oC ces qhov kub thiab txias T2 thiab T3 yog ...
A. T 2 = 54,26 o C, T 3 = 31,4 o C
B. T 2 = 31,4 o C, T 3 = 54,26 o C
C. T 2 = 32,4 o C, T 3 = 54,26 o C
D. T 2 = 56,26 o C, T 3 = 31,4 o C
E. T 2 = 54,26 o C, T 3 = 30,4 o C
Kev Sib Tham
Nws paub tias:
T1 = 100 oC
T4 = 20 oC
4 k A = 2 k B = k C
Yog tias k C = 4, k B = 2, k A = 1
Nug: T 2 thiab T 3
Lus teb:
Cov mis rau kev hloov pauv cua sov los ntawm kev sib txuas lus:
Cov Ntaub Ntawv:
Q/t = tus nqi hloov cua sov, k = kev ua kom muaj cua sov, A = thaj tsam hla, T 1 = qhov kub pib, T 2 = qhov kub kawg, l = qhov ntev ntawm tus pas.
Qhov ntev (l) thiab thaj tsam hla (A) sib npaug yog li lawv raug tshem tawm ntawm qhov sib npaug.
Siv cov qauv no los xam qhov kub.
Xav txog cov pas hlau A thiab B.
Xav txog cov pas nrig hlau B thiab C.
Tshem tawm qhov sib npaug 1 thiab qhov sib npaug 2:
Xam T 2 siv kab zauv 1:
Cov lus teb yog lawm yog A.
Qhov chaw nug lus:
Cov Lus Nug Txog Kev Xeem Physics Hauv Tebchaws Rau Tsev Kawm Ntawv Theem Siab/Tsev Kawm Ntawv Theem Siab Ua Haujlwm
