fkdñ,fha fnod yeÍu i|yd h' 61

4 tallh ;dmc Yla;sh uekSfï yd ixl%duKh lsÍfï l%u

;dmc Yla;sh uekSfï ydixl%duKh lsÍfï l%u

4 mßÉfþohfN!;sl úoHdj

ksmqK;dj

;dmc Yla;sh uekSfï yd iïfm%aIKh lsÍfï l%u Ndú;hg .kshs'

ksmqK;d uÜgï úIh wka;¾.;h

4' 1' ;dm yqjudrej ksid isÿ jk

WIaK;aj fjkia ùï ukshs'

4' 2' jia;=jla ,nd .kakd ;dm

m%udKh .Kkh lrhs'

4' 3' ;dmc Yla;sh ld¾hlaIu

j fhdod .kshs'

² WIaK;aj ixl,amh

² WIaK;aj mßudK

² fi,aishia mßudKh - (0C)

² *erkayhsÜ mßudKh - (0F)

² WIaK;ajh uekSfï wka;¾ cd;sl tallh (K)

² ;dm m%udKh

² ;dm Odß;dj

² úYsIag ;dm Odß;dj C

² ;dm m%udKh (Q = mcθ)

² ;dmh ixl%duKh jk l%u

² ikakhkh

² ixjykh

² úlsrKh

² ;dmh ixl%duKh jk l%u Ndú;hg .kakd wjia:d

61

fN!;sl úoHdj

62 fkdñ,fha fnod yeÍu i|yd h'

;dm yqjudrej ksid isÿ jk WIaK;ajfjkia ùï

4.1

WIaK;aj ixl,amhl%shdldrlu 1

n÷ka ;=klg isis,a c,h" WKq c,h

iy we,a uereKq c,h f.k

m<uqfjka we,a c,h;a WKq c,h;a

w;a fofla weÕs,sj,ska iam¾Y lr

n,kak' we,a c,fha WKqiqu wvq

nj;a WKq c,fha WKqiqu jeä nj;a

wmg ±fka' bka miq we,a uereKq

c,h iam¾Y l< úg ±fkkafka

ljrla o@

ie'hq( b;d by< WKqiqul ;sfnk

c,h iam¾Y lsÍfuka j<lskak'n÷kaj, c,fhys WKqiqfï fjki wm ±k

.;af;a iam¾Yfhks'

we,a c,hg jvd WKq c,fha fjki ljrla

o@

c,h WKq lr .;af;a hï ;dmlhl

wdOdrfhks' c,h r;a lrk úg tu c,h

fj; ;dm Yla;sh ,eîu ksid c,h WKqiqï

úh'

;dmh Yla;s m%fNaohla nj wms oksuq' ;dmfhka

fkdfhla ld¾h l< yels h' hï jia;=jl

WIaK;ajh by< hkafka thg ;dmh ,eîu

ksid h' hï jia;=jl WIaK;ajh wvq jkafka

thska ;dmh bj;a j hdu ksid h'

r;a jQ jia;=jla iam¾Y lsÍfï § wfma w;g

WKqiqula ±fkkafka thska wfma w;g ;dmh

,eîu ksid h' whsia lene,a,la w;ska we,aÆ

úg iS;, ±fkkafka wfma w;aj,ska whsia

lene,a,g ;dmh bj;a j hdu ksid h'

wjia:d úm¾hdihl § yer hï jia;=jlg ;dmh ,efnk

úg tys WIaK;ajh by< hhs' hï jia;=jlska ;dmh

bj;a jk úg tys WIaK;ajh my< nishs'

WKqiqu yd isis, ms<sn| j wmf.a ±kSu iam¾Y

bkaøshj,g ±fkk ixfõok u; r|hs' WKq

c,h" u|la WKq c,h" we,a uereKq c,h"

isis,a c,h jeks jpkj,ska .uH jkafka

WKqiqï m%udK iei£ula nj by; i|yka

l%shdldrlfuka meyeÈ,s jkafka h'

WKq c,h

isis,a c,h

we,a

uereKq c,h

4'1 rEmh iam¾Yfhka WIaK;ajh ms<sn|

ksjerÈ ñKqula ,nd.; fkd yel'

62

fkdñ,fha fnod yeÍu i|yd h' 63

4 tallh ;dmc Yla;sh uekSfï yd ixl%duKh lsÍfï l%u

WIaK;aj mßudK

WIaK;aj mßudK lsysmhla we;'

1' fi,aishia mßudKh

2' *erkayhsÜ mßudKh

3' fl,aúka mßudKh

iam¾Y ixfõokfhka WIaK;ajh ;SrKh lsÍu wmyiqnj Tng ±ka meyeÈ,s h' úoHd;aul lghq;=j, §WIaK;ajh b;d ksrjoH f,i uekSug wjYH fõ' tai|yd WIaK;aj mßudK ;sìh hq;= h' WIaK;ajmßudKj,ska ixLHd;au; f,i WIaK;ajh ksrEmKhl< yels h'

4'2 rEmh wekav¾ia fi,aishia

±kg nyq, jYfhka Ndú;d jk WIaK;aj mßudKh fi,aishia ^fyda fikaáf.%aÜ&mßudKhhs'

tu mßudKfha (l w.hka fi,aishia wxYl ^0C& f,i ±lafõ'

iïu; jdhqf.da,Sh mSvkh riÈh ñ,sógr 760 hk wjia:dfõ§"l my< ia:djr ,laIHh ( whsia c,h njg m;ajk WIaK;ajh ̂ c,fha øjdxlh&

0 0C

l by< ia:djr ,laIHh ( c,h yqud,h njg m;ajk WIaK;ajh ̂c,fha ;dmdxlh&100 0C

l whsia Èhjk WIaK;ajhg jvd wvq WIaK;aj j, mj;sk øjH fndfyduhlawe;' tajdfha WIaK;aj iDK fi,aishia w.hka .kS'

l fi,aishia mßudKh" ia:djr ,laIH fol w;r mr;rh fldgia fyda wxYl100 lg fnod we;'

l zzfikaáf.%aâZZ hk jpkfha w¾:h jkafka zzfldgia 100ZZ hkqhs'l fmr nyq, jYfhka Ndú;d l< WIaK;aj mßudKh *erkayhsÜh'

fuu mßudKfha (

l w.hka *erkayhsÜ wxYl ^0F& f,i ±lafõ'iïu; jdhqf.da, mSvkh riÈh ñ,sóg¾ 760 hk wjia:dfõ§

l my< ia:djr ,laIHh ( whsia ys øjdxlh 32 0Fl by< ia:djr ,laIHh ( c,fha ;dmdxlh 212 0F

fi,aishia yd *erkayhsÜ mßudK w;riïnkaO;dj

fi,aishia mßudKfha wxYl 100 la iudk jkafka*erkayhsÜ mßudKfha wxYl ^212 - 32& } 180 g h'

4'3 rEmh fl,aúka idñjrhd ̂ú,shï f;dïika&

WIaK;aj mßudKh tallh

fi,aishia

*erkayhsÜ

fl,aúka

0 C0 F

K

fi,aishia mßudK 1000 } *erkayhsÜ mßudKfha 1800

tu ksid fi,aishia mßudKfha 50 } *erkayhsÜ mßudKfha 90

63

fN!;sl úoHdj

64 fkdñ,fha fnod yeÍu i|yd h'

*erkayhsÜ wxYl fi,aishia wxYlj,g yerùfï iQ;%h

0 C = (0F - 32 ) x 59

fi,aishia 400 la *erkayhsÜj,g mßj¾;kh lruq'

fi,aishia mßudKfha 400 } *erkayhsÜ mßudKfha wxYl 40 «9

5*erkayhsÜ mßudKfha my< wp, ,laIHh 32 ksid by; lS w.hg wxYl 32 la

tl;= lsÍfuka *erkayhsÜj,ska WIaK;ajh ,efí'

tneúka 400C } 72 + 32 } 104 0 F

WIaK;ajh ms<sn| cd;Hka;r tAllh

WIaK;ajh ms<sn| cd;Hka;r tallh fl,aúka (K) fõ' th oK f,i ,shkqfkd,efí' fl,aúka mßudKh ksrfmalaI WIaK;aj mßudKh f,i ye¢kafjk w;r"tys wju WIaK;ajh tkï 0 K ksrfmalaI Y=kHh f,i ye¢kafõ' ksrfmalaI Y=kHhhkq ffioaOdka;sl jYfhka wju WIaK;ajh jk w;r" Bg wvq WIaK;aj mej;shfkdyelsh' mÍlaIKd;aulj ksrfmalaI Y=kHh olajd jia;=jla isis,a l< fkd yelsh'tkuq;a ksrfmalaI Y=kHhg b;d wdikak WIaK;ajhka mÍlaIKd;aulj ,ndf.k we;'

cd;Hka;r ms<s.ekSu wkqj 0 K iudk jkQfha fi,aishia mßudKfhka - 273.15 0C fyda*erkayhsÜ mßudKfhka - 459.67 0F hk w.hkag h' fl,aúka mßudKh yd fi,aishiamßudKfha wxYlhl mrdih iudkh wdikak w.hla f,i 0 K = - 273 0C f,i .;yelsh'

tneúka 400C } 40 « 9

5+ 32 0 F

fi,aishia wxYl *erkayhsÜ wxYlj,g yerùfï iQ;%h

0 F = ( « 0C ) + 329

5

*erkayhsÜ 950 la fi,aishiaj,g mßj¾;kh lruq'

*erkayhsÜ 950 } fi,aishia ^950 - 32& «5

9tneúka 950 F } ^950 - 32& «

tneúka 950 F } 63 « } 35 0 C

5

95

9

0C isg K : K = 0C + 273

K isg 0C : 0C = K - 273

fl,aúka WIaK;ajh (K) = fi,aishia WIaK;ajh 0C + 273

c,fha ;dmdxlh

ñksia isref¾ idudkH WIaK;ajh

c,fha øjdxlh

ksrfmaCI Y+kHh

fi,aishia mßudKh0 C

100

36'90

273'15

100

fl,aúka mßudKh

K

373

309'9

273

0

100

*erkayhsÜ mßudKh0 F

212

98'4

32

459'67

180

m%Odk WIaK;aj mßudK w;r ixikaokhla

64

fkdñ,fha fnod yeÍu i|yd h' 65

4 tallh ;dmc Yla;sh uekSfï yd ixl%duKh lsÍfï l%u

l riÈh øjhla f,i fh¥ WIaK;ajudk by< WIaK;aj uekSug fhda.H jk w;ruoHidr øjhla f,i fh¥ WIaK;ajudk wvq WIaK;aj uekSu i|yd fhda.H fõ'

l úoHd.drj, Ndú;jk WIaK;ajudk yd ffjoH WIaK;ajudk nyq, j Ndú;jk ùÿre øj WIaK;ajudk fõ'

ffjoH WIaK;ajudkfhys ,laIK

l tys WIaK;aj mrdih fláh' ^35 0C - 43 0C&

l flaIsl isÿf¾ A ,laIfhys ishqï keïula we;'

l WmlrKfha ixfõÈ;dj jeälsÍu i|yd mßudKh wkq fldgiaj,g fnod we;'fuu WIaK;ajudkh Ndú; lr frda.shl=f.a YÍr WIaK;ajh uekSfï§ m%idrKh

jk riÈh l| u.ska we;slrk n,h ksid A ,laIh yryd riÈh myiqfjka .uka lrhs'

kuq;a bÈßhg .sh riÈh l| kej; n,anh ;=<g tAu A ,laIHfhys we;s keïu u.ska

j,lajhs' tu ksid WIaK;ajudkh frda.shdf.a isrefrka bj;a l< miqj;a WIAK;aj

mdGdxlh lshùug mq̈ jk' kej; Ndú;hg .ekSug fmr riÈh l| keïfuka wdmiaig

heùu i|yd WIaK;ajudkh fyd¢ka .eiaish hq;= h'

WIaK;ajudkhla Ndú; lsÍfï § ie,ls,su;a úh hq;= lreKq

l ukskq ,nk WIaK;ajhg .e,fmk" WIaK;aj mrdihla iys; WIAK;ajudkhlaf;dard .; hq;= h'

l fkdokakd WIaK;ajhla uekSfï § úYd, WIaK;aj mrdihla iys;WIAK;ajudkhlska uek miqj jvd ksjerÈ ñkqï ,nd.ekSu i|yd tu WIaK;ajhg.e,fmk WIaK;ajudkhla Ndú; l< hq;= h'

l WIaK;ajudk wêl f;rmqï yd .eàïj,g ,la fkdjk mßÈ Ndú; lsÍu iywiqrd ;eîu l< hq;= h'

riÈh yd uoHidrj, ;dmdxl yd ysudxl

øjh ysudxlh

riÈh

uOHidr

- 39 0C

-115 0C

;dmdxlh

3570C

60 0C

WIaK;ajudk

l WIaK;ajh m%udKd;aulj uekSug Ndú; lrk WmlrK WIaK;ajudk f,i

ye¢kafõ'

l nyq, f,i Ndú;jk WIaK;ajudk j¾.h ùÿre-øj WIaK;ajudkhhs'

l fuys øjh f,i riÈh fuka u uoHidr o Ndú; lrhs'

65

fN!;sl úoHdj

66 fkdñ,fha fnod yeÍu i|yd h'

jia;=jla ,nd .kakd;dm m%udKh .Kkh lsÍu

4.2

jia;=jl ;dm Odß;dj

tl u øjH j¾.fha úúO ialkaOj,g iudk ;dm m%udK iemhQ úg tajdfha WIaK;ajh

by< hdu iudk o@ fuh fidhd ne,Su i|yd ir, l%shdldrlula my; ±lafõ'

l%shdldrlu 2

iudk l=vd îlr ;=kla f.k tajd lsrd .kak' bka miq îlr ;=kg ms<sfj,ska c,h 0.1 kg, 0.2

kg iy 0.3 kg oukak' fï ;=kg u WIaK;ajudk oud tl iudk YS>%;djlska ;dmh imhk

odylhlska tu n÷ka r;a lrkak' iudk ld,hlg miq tajdfha WIaK;ajh by< kexù we;s

m%udKh n,kak' wvq u c, ialkaOh we;s îlrfhys jeä WIaK;ajhla o jeä c, ialkaOhfhys

wvq WIaK;ajhla o olakg ,efí' ñka meyeÈ,s jkafka tl u øjH j¾.fha fjkia ialkaOj,

;dm Odß;d wiudk njhs' ñka ks.ukh l< yelafla l=ula o@

hï jia;=jl WIaK;ajh fi,aishia wxYl tllska tkï" fl,aúka (K) tllska by<

kexùug wjYH ;dm m%udKh tu jia;=fõ ;dm Odß;dj (C) f,i ye`oskafõ'

kso( hï n÷kl WIaK;ajh 10C lska tkï" fl,aúka (K) tllska kexùug jqjukd

;dm m%udKh cQ,a 500 la kï tu n÷fka ;dm Odß;dj } 500 JK −1

4'5 rEmh øjhl ;dm Odß;dj tys ialkaOh u; r|d mj;S'

;dm m%udKh } ;dm Odß;dj « WIAK;aj fjki

Q (E) } C θ

66

fkdñ,fha fnod yeÍu i|yd h' 67

4 tallh ;dmc Yla;sh uekSfï yd ixl%duKh lsÍfï l%u

úYsIag ;dm Odß;dj

hï øjH j¾.hl úYsIag ;dm Odß;dj hkq tu øjH j¾.fha

lsf,da.%Eï 1 l WIaK;ajh fl,aúka tllska ̂tkï fi,aishia

wxYl tllska& kexùug jqjukd ;dm m%udKhhs'

kso( c,h 1 kg l WIaK;ajh 10C lska ̂ 1 K lska& kexùug

jqjukd ;dm m%udKh 4200 J ls'

tkï c,fha úYsIag ;dm Odß;dj } 4200 J kg−1 K−1

we¨ñkshï 1 kg l WIaK;ajh 10C lska ^1 K lska&

kexùug jqjukd ;dm m%udKh 900 J ls'

we¨ñkshïj, úYsIag ;dm Odß;dj } 900 J kg−1 K−1

;U 1 kg l WIaK;ajh 1 0C lska ̂ 1 K lska& kexùug

jqjukd ;dm m%udKh 400 J ls'

tkï ;Uj, úYsIag ;dm Odß;dj } 400 J kg-−1 K−1

² øjH j¾. lsysmhlúYsIag ;dm Odß;dj

øjH j¾.h úYsIag ;dm Odß;dj

(Jkg−1 K−1)

c,h

we¨ñkshï

hlv

;U

Bhï

fldkal%SÜ

ms;a;,

whsia

lrosh

;=;a;kd.ï

4200

900

460

400

130

850

380

2100

3900

380

úYsIag ;dm Odß;dj i|yd Ndú; l< hq;= iïu; tallh J kg−1 K−1 h' bka woyia

lrkafka hï øjH lsf,da.%Eï tll WIaK;ajh fl,aúka tllska by< kexùug

jqjukd ;dm m%udKh flf;la o hkakhs'

ta wkqj c,fha úYsIag ;dm Odß;dj } 4200 J kg−1 K−1 ^4200 J kg−1 0C−1&

c,h 1 kg la 10 C lska kexùug wjYH ;dmh = 4200 J

c,h 5 kg la 10 C lska kexùug wjYH ;dmh =5 × 4200 J

c,h 5 kg la 200 C lska kexùug wjYH ;dmh = 5 × 4200 × 20 J

= 420, 000 J

fuu ms<s;=r (420, 000) ,enqfKa [5 × 4200 × 20]

5 × 4200 × 20

ialkaOh ú';d'Od' WIaK;aj fjki

;dm m%udKh = (mcθ)

m c θ

úYsIag ;dm Odß;dj iy ;dm Odß;dj w;r iïnkaOh

úYsIag ;dm Odß;dj hkq hï øjH j¾.hl lsf,da.%Eï 1 (1kg)l WIaK;ajh 1K

^10C& lska kexùug wjYH ;dm m%udKh fõ' jia;=jl WIaK;ajh 1K ̂ 10C& lska

lska kexùug wjYH ;dm m%udKh tu jia;=fõ ;dm Odß;dj kï fõ'

tneúka ;dm Odß;dj (C) } ialkaOh (m) « úYsIag ;dm Odß;dj (c)

C } mc

fN!;sl úoHdj

68 fkdñ,fha fnod yeÍu i|yd h'

^1& c,h 4 kg la 5 0C lska kexùug jqjukd ;dmh fidhkak'

^jqjukd ;dmh& Q = mcθ

= 4 kg × 4 200 J kg−1 K−1 × 5 K

= 84 000 J

^2& ;U 4 kg la 30 0C isg 50 0C f;la kexùug jqjukd ;dmh fidhkak'

^jqjukd ;dmh& Q = mcθ

= 4 kg × 400 J kg−1 K−1 × 20 K

= 32 000 J

^3& ;dm Yla;sh 55200 J la hlvj, ljr ialkaOhlg ,nd ÿka úg WIaK;ajh 20 0C

isg 50 0C olajd kexfõ o @

^jqjukd ;dmh& Q = mcθ

55200 J = m × 460 J kg−1 K−1 × 30 K

m =55 200 J

460 J kg−1 K−1 × 30 K

= 4 kg

^4& fmd,a f;,a 6 kg l ;dm Odß;dj fidhkak'

^;dm Odß;dj& C = mc

= 6 kg × 2 200 J kg−1 K−1

= 13200 J K−1

^5& 1.5 kg l ialkaOhla iys; ;U Ndckhl 30 0C c,h 2 kgla we;' fuu c,fha

WIaK;ajh 100 0C f;la kexùug jqjukd ;dmh fidhkak'

Ndckh ,nd .kakd ;dmh Q = mcθ

= 1.5 kg ×400 J kg−1 K−1 × 70 K

= 42 000 J

c,h ,nd .kakd ;dmh = 2 kg ×4200 J kg−1 K−1 × 70 K

= 588 000 J

jqjukd ;dmh = 42 000 J + 588 000 J

= 630 000 J

.eg¨ - úi÷ï

fkdñ,fha fnod yeÍu i|yd h' 69

4 tallh ;dmc Yla;sh uekSfï yd ixl%duKh lsÍfï l%u

l ùÿre" c,h" ma,diaála" ±j" jd;h wdÈh ÿ¾j, ;dm ikakdhl fõ'

l hï øjHhla iújr kï o tys ;dm ikakdhl;dj wvq h'

kso ( iújr fldkal%SÜ (aereated concrete) kQ,a" ùÿre fl¢" iaghsfrdf*daï

;dmh ixl%duKh jk l%u4.3

ikakhkh

f,day oKavl hï fldgila r;a lrk úg tu fmfofia we;s ksoyia bf,lafg%dak

pd,l Yla;sh ,ndf.k fõ.fhka lïmKh ùug mgka .kS' tAjd wyUq f,i me;sfrñka

wfkl=;a ksoyia bf,lafg%dak iuÕ .efgñka tAjdg Yla;sh ixl%uKh lrhs' fufia

>k øjH ;=<ska wxY= tla ia:dkhl isg ;j;a ia:dkhlg .uka lsÍulska f;drj ;dmh

.uka lsÍfï hdka;%Kh ;dm ikakhkh kï fõ'

;dm ixl%duKh hkq ;dmh ;eklska ;j;a ;eklg .uka lsÍu hs' ;dmh ixl%duKh

jk l%u ;=kls'1& ikakhkh (Conduction)

2& ixjykh (Convection)

3& úlsrKh (Radiation)

l f,day" b;d fyd| ;dm ikakdhl fõ' ̂ ߧ"

;U" we¨ñkshï" r;arka yd hlv&

l ñksrka kue;s ldnka iajrEmh yereKq

úg wksla wf,day ;dm l=ikakdhl fõ'

tfiajkafka uqla; bf,lafg%dak fkdue;s

ksid h'

l ñksrka uqla; bf,lafg%dak j,g .uka

l< yels neúka thg ;dmh ikakhkh

l< yelsh'

4'7 rEmh f,day ;=<ska ;dmh

blaukska ikakhkh fõ' tneúka

f,dayuh n÷ka blaukska r;afõ'

4'6 rEmh ;dm ikakhkh

øjHhla ;=<ska fl;rï fyd¢ka ;dmh ikakhkh

lrkafka±hs tajd we,a,Sfuka lsj yelsh' ksoiqkla

f,i fodrl f,day w.=, we,a,Sfï§ iS;,la

±fkkafka th fyd¢ka ;dmh ikakhkh lrk

ksidh fodfrys ±j fldgi we,aÆ úg iS;,la

fkd±fkkafka th ÿ¾j, ;dm ikakdhlhla ùu

ksidh'

fN!;sl úoHdj

70 fkdñ,fha fnod yeÍu i|yd h'

l%shdldrlu 3

rEmfha ±lafjk mßÈ c, mDIaG fmfoi r;a lrk

úg tu c, mDIaG m%foaYfha c,h r;a ù kgoa§;a"

;U lïì ±,a .=,sfhka jg lr we;s whsia lene,a,

Èh fkdù mj;S' ta wehs@ c,fha ikakdhl;dj b;d

wvq neúks' c,h l=ikakdhlhls'

ixjykh (Convection)

øj ;=< ;dmh ixl%duKh jkafka ixjykh u.sks'

c, n÷kla r;a lrk úg ;dmlfhka ;dmh ,nd

f.k r;a jk c, wKqj, >k;ajh wvqjk neúka

c,h ;=< by<g .uka lrhs' >k;ajfhka jeä isis,a

c, wKq my<g meñfKhs' tys m%;sM,h c,h ;=<

ixjyk Odrd ixjyk Odrd ixjyk Odrd ixjyk Odrd ixjyk Odrd (Convection Currents) we;s ùuhs'

îlr m;=f,a l=vd fldkaäia leg ;nd bá

iaj,amhlska th wdjrKh lrkak' bkamiq c,h

r;a lrkak' túg ixjyk Odrd we;sjk wdldrh

o¾Ykh l< yels h' ^4'10 rEmh&

Tn okakjd o@

.skss mE.Sï lrkafka 7000C ys

muK WIaK;ajhl mj;sk

wÕ=re u; h' wÕ=rej, ;dm

ikakdhl;dj b;d wvq h' ;j o

.sks md.k whf.a mdo wÕ=re

u; .efgkafka b;d iq¿

ld,hla muKs' tneúka .sks

mE.Sfï § ydkshla jk ;rï

;dmhla iug fkd,efí'

4'10 rEmh c,h r;a lrk úg c,h ;=< we;s jk ixjyk Odrd

4'9 rEmh .sks f.dvla wi< jd;fha

ixjyk Odrd we;s ùu

.sksf.dvla we;s ;ekla .ek is;kak' .sksf.dfvka

;dmh ,nd .kakd jdhq wKq r;a ù by<g .sh úg

tajdhska fjk;a wxY=j,g ;dmh fohs'

r;a jQ wxY= by<g .uka lr ;dmh ixl%duKh jk

l%uh ixjykh f,i ye¢ka fõ' ^4'9 rEmh&

;U lïì ±,a

.=,shlska jg l<

whsia lene,a,r;a lsÍu

WKqiqï c,h

by<gisis,a c,h

my<g

4'8 rEmh c,h ;dm l=ikakdhlhls'

bá wdjrKh

l< fldkaäia

legh

fkdñ,fha fnod yeÍu i|yd h' 71

4 tallh ;dmc Yla;sh uekSfï yd ixl%duKh lsÍfï l%u

rEmfha ±lafjk mßÈ îlrhl ueo ldâfndaâ

lene,a,la ysr lr ;nkak' ldâfndaâ lene,af,ka

fjka jQ m%foaY fol A yd B hkqfjka kï lruq'

B fldgfia m;=f,a bámkaoula w,jd th o,ajkak'

bá mkaoï ±,af,ka ;dmh ,nd .kakd B fldgfia

jd;h r;a ù by< wefoa' túg iS;, jd; wxY= A

me;af;a isg ±,a, wi,g we§ ths' tys § r;a jk jd;

wxY= tu ia:dkfhka by<g we§ hhs' rEmfha ±lafjk

mßÈ ±,a jQ y÷ka l+rl ÿu .uka lrk wdldrfhka

jd; wxY=j, p,s; rgdj wdo¾Ykh l< yels h'

úlsrKh (Radiation)

ikakhkh iy ixjykh hk l%u foflka ;dmh ixl%duKh ùug hï udOHhla

mej;Su wjYH fõ' úlsrKh uÕska ;dmh ixl%duKh ùug udOH wxY=j, iyNd.s;ajhla

wjYH fkdfõ' ßla; m%foaY yryd jqj o úlsrKh u.ska ;dmh ixl%duKh úh yels h'

iQ¾hhdf.a isg fmdf<djg ;dmh <Õd jkafka o úlsrKh u.sks'

r;a jQ jia;=jla wi, isák úg wmg tys WKqiqu ±fkkafka úlsrKh u.ska wfma YÍrh

fj; ;dmh .,d tk neúks'

Wÿkla <Õ isák úg" tuÕska wmg ;dmh ,efnkafka úlsrKh uÕsks'

r;a ù we;s ´kE u jia;=jla ;dmh úlsrKh lrhs'

;dmh úlsrKh ùu hkq ;rx. wdldrfhka ;dmh .uka lsÍu hs' fï ;rx. wfOdarla;

;rx. (Infra red waves) fõ' my; ±lafjk l%shdldrlu lr n,uq'

4'11 rEmh jd;h ;=< ixjykh isÿ ùu

wdo¾Ykh lsÍu

A

B

l%shdldrlu 4

A,B yd C tl u m%udKfha áka n÷ka ;=kls'

tll (A) msg; mDIaGh l¿ lrkak' fojk

tflys (B) msg mDIaGfha iqÿ ;Ska; wdf,am

lrkak' ;=kajk tfla (C) mDIaGh Tm

È,sfik mDIaGhla lr .kak' áka n÷ka ;=fka

Wv me;af;a tl u m%udKfha isÿr ne.ska

lmd bj;a lrkak' lsr, wen ;=<ska

WIaK;ajudkh ne.ska we;=¿ lr tu wen

by; lS isÿrej,g .id ;nkak' fuu áka

n÷ka ;=k ysre t<sfha tl u ;ekl iudk

ld,hla ;nd Bg miq WIaK;ajudkj,

mdGdxl ,nd .kak'

A B C

4'12 rEmh

fN!;sl úoHdj

72 fkdñ,fha fnod yeÍu i|yd h'

A n÷fka WIaK;ajudk mdGdxlh wfkla folg jvd jeä nj olakg ,efnkq we;' B

<Õg B n÷fka WIaK;ajh jeä h' WIaK;ajudkfha mdGdxlh wvq u C ys h'

ñka meyeÈ,s jkafka l¿ mDIaG u.ska úlsrK ;dmh Wrd .kakd YS>%;dj wêl nj;a iqÿ

mdg mDIaG úlsrK ;dmh Wrd .kakd YS>%;dj Bg jvd wvq nj;a Tm mDIaG u.ska úlsrK

;dmh Wrd .kakd fõ.h fndfyda wvq nj;a h'

áka n÷ka ;=k ksfjkakg ;enQ úg blaukska u ksfjkafka l¿ n÷k nj;a B <Õg

ksfjkafka iqÿ n÷k nj;a wka;sug ksfjkafka È,sfik n÷k nj;a ±l .; yels h'

fuhska meyeÈ,s jkafka l¿ mDIaGj,ska ;dmh úlsrKh jk YS>%;dj jeä u nj;a iqÿ

mDIaGj,ska ;dmh úlsrKh jk YS>%;dj Bg jvd wvq nj;a È,sfik mDIaGj,ska ;dmh

úlsrKh ùfï YS>%;dj Bg;a jvd wvq nj;a h'

is;kak

jvd blaukska ksfjkafka l¿ yd r¿ mDIaGhla iys; n÷kl ;sfnk wdydr o"

ke;fyd;a È,sfik iqug mDIaGhla iys; n÷kl we;s wdydr o@

l WKq j;=r fnda;,fha l%shdj

WKq j;=r fnda;,fha we;s rn¾

wdOdrl yd mßjdrl wenh ksid"

ikakhkh iy ixjykh uÕska tys

we;s WKq øjfhka ;dmh bj;a ù

hdu wvq ù we;'

oaú ia:r ùÿre ì;a;s w;r wjldYfha

jd;h bj;a lr ßla;hla lr ;sîu

ksid ikakhkh yd ixjykh u.ska

;dmh bj;a ùu j<lajd we;'

kuq;a ßla;h yryd ;dmh úlsrKh

u.ska bj;a j hd yels h' fuh wju

lsÍug rEmfha ±lafjk mßÈ oaú ia;r

ì;a;sfha we;=,a mDIaGj, ߧ wdf,am

lr we;' fuf,iska WKq j;=r

fnda;,hla ;+< oud we;s WKq oE

WKqfjka o isis,a oE isis,a f,i o

fndfyda fõ,djla mj;S'

l f,day ;yvqj, ls%hdj

f,day ;yvq fiú,s l< jy,hla r;a j we;s úg tu ksji ;=< fndfyda WKqiqï h' Bg

fya;=j r;a jQ f,day ;yvq ;=<ska ;dmh úlsrKh ùuhs'

4'13 rEmh WKq j;=r fnda;,h

mßjdrl wenh

øjh

ßla;h

ߧ wdf,ams; mDIaG

rn¾ fyda ma,diaála

wdOdrlh

;dm ixl%duKfha fh§ï

fkdñ,fha fnod yeÍu i|yd h' 73

4 tallh ;dmc Yla;sh uekSfï yd ixl%duKh lsÍfï l%u

wNHdi

idrdxYh

² jia;=jlg ;dmh ,efnk úg tys WIaK;ajh by< hhs'² jia;=jlska ;dmh bj;a jk úg tys WIaK;ajh my< nishs'² WIaK;ajudk mßudK fufia h'

fi,aishia mßudKh" *erkayhsÜ mßudKh' wka;¾ cd;sl mßudKh ̂fl,aúkamßudKh&

² ta wkqj WIaK;aj tallh 0C, 0F iy K fõ'² jia;=jl ;dm Odß;dj hkq tu jia;=fõ WIaK;ajh 1 K lska kexùug wjYH

;dm m%udKhhs'² úYsIag ;dm Odß;dj hkq hï øjH j¾.hl 1 kg l WIaK;ajh 1 K lska

kexùug jqjukd ;dmhhs'

² ;dm m%udKh" Q } mcθ

² ;dmh ixl%duKh jk l%u ikakhkh" ixjykh yd úlsrKh fõ'

l YS;lrKhl ls%hdj

YS;lrKhla ;=< ;nk øjHj,ska ;dmh bj;a j tajdisis,a jk nj wms oksuq' tu øjHj,ska ;dmh bj;ajkafka YS; ldrl øj u.ska ;dmh Wrd .ekSu ksidh' tu øj .,d hkafka" k< moaO;shla Èf.a h' fïk< YS;lrKfha miq mi mDIaGfhys olskakg ,efí'

fï k<j, ndysr mDIaGh l¿ meye;s h' tu l¿meyeh ksid ;dmh iS.% f,i úlsrKh fõ'

l úlsrlh

r:jdykj, úlsrlj, (Radiators) mDIaG o l¿meye;s h' ;dmh fõ.fhka úlsrKh ùu i|yd tajdtfia ilia lr we;'

l r;alsÍu i|yd uq¿;ekaf.hs Ndú; lrk WmlrKj, w;ska iam¾Ylrk fldgia

;dm mßjdrl øjHj,ska idÞ we;'

l uqyqÿ fjr< wdYs%; j f.dv iq<x yd uqyqÿ iq<x we;sùug fya;=j jkafka ixjyk jdhq

Odrd we;sùuhs'

l mDÓú lfnd,g we;=<;ska jQ uekag,fha úh,kh jQ mdIdK ;=< yg.kakd ixjyk

Odrd fya;=fjka N+ ia:r p,kh ùu yd N+ñ lïmd we;s fõ'

úYsIag ;dm Odß;d w.hka (

c,h 4200 JKg− 1 K− 1 " ùÿre 700 J Kg− 1 K− 1" fmd,af;,a 2200 J Kg− 1 K− 1

1' i. úYsIag ;dm Odß;dj hkq l=ula ±hs y÷kajkak'

ii. a) jia;=jl ;dm Odß;dj 8000 J 0 K− 1 fõ' fuhska woyia lrkafka l=ula o@

b) fï jia;=fõ WIaK;ajh 30 0C isg 50 0C f;la kexùug jqjukd ;dm

m%udKh .Kkh lrkak'

4'14 rEmh YS;lrKh

úlsrlh

Tfí ±kqu i|yd

fN!;sl úoHdj

74 fkdñ,fha fnod yeÍu i|yd h'

iii. WIaK;ajh uekSfï wka;¾ cd;sl tallh l=ula o@

iv. wka;¾ cd;sl tallh iy fi,aishia wxYl w;r iïnkaO;dj olajkak'

v. my; ±lafjk fi,aishia wxYl *erkayhsÜ wxYlj,g yrjkak'

a) 37 0C b) 30 0C c) 100 0C d) -10 0C

vi. fuu *erkayhsÜ wxYl fi,aishia wxYlj,g yrjkak'

a) 113 0F b) 131 0F c) 77 0F d) 140 0F

2' i. 7.5 kg ialkaOhla we;s ;U Ndckhl WIaK;ajh 300C isg 800C f;la by<

kexùug wjYH ;dm m%udKh fidhkak'

ii. 100 0C c,h 0'5 kg la 30 0C olajd ksfjk úg ljr ;dm m%udKhla bj;a

jkafka o@

iii. 0 0C c,h 0'75 kg la 100 0C njg m;a ùug wjYH ;dm m%udKh flf;la o@

iv. 1.5 kg ialkaOhla iys; ;U Ndckhla ;=< 30 0C c,h 0.75 kg we;' fuu

c,h kgk f;la r;a lsÍug wjYH ;dm m%udKh flf;la o@

v. 0.5 kg ialkaOhla we;s ùÿre Ndckhl 30 0C c,h 1.5 kg la we;' fï c,h

kgk f;la r;a lsÍug wjYH ;dm m%udKh fidhkak'

vi. ialkaOh 0.5 kg jk ms;a;, Ndckhl 30 0C fmd,af;,a 0.8 kg la we;' fï

fmd,a f;,a 50 0C olajd r;a lsÍug wjYH ;dm m%udKh fidhkak'

vii. 0 0C c,h 2 kg lg 100 0C c,h 2 kg la ±uQ úg ;dm ydkshla ke;ehs i,ld

ñY%Kfha WIaK;ajh fidhkak' Ndckfha ;dm Odß;dj fkdi,ld yßkak'

3' i. hlv iy ;U w;ßka ;dm ikakdhl;dj jeä øjHh fidhd ne,Sug ir,

mÍlaIKhla ,shkak'

ii. ߧ" ;U" we¨ñkshï" r;arka wd§ f,day ukd ;dm ikakdhl jkafka h' Bg

fya;=j myokak'

iii. c,h l=ikakdhla nj fmkajd §ug Tn ie,iqï lrk mÍlaIKhl mshjr

,shkak'

iv. jd;h ;=< ixjyk Odrd we;s ùu fmkajd §ug Tn lrk ir, mÍlaIKhla

,shkak'

v. fudag¾ r:j, úlsrl iy YS;lrKj, úlsrl l¿ meye;s h' Bg fya;=j

myokak'

vi. ;¾fudaia *a,dial=jla fyj;a WKq j;=r fnda;,hlska ;dmh ydks ùu j<lajd

we;af;a ljr l%uj,ska o@