S. o r I f j o n o V elektromagnitizm
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(58.3) A m a liy m a s a la la rd a I a ^ I » | a ^ | b o ‘lib, ta sh q i k o n ta k t p o t e n s ia lla r farqi k o 'p r o q a h a m iy a tg a ega. E le k tr to k la ri b o 'l m a g a n d a b irin c h i m e ta ln in g b u t u n h a jm id a p o te n s ia l d o im iy ( sial d o im iy (cp2) b o 'l a d i , p o te n s ia lla r fa rq i esa fa q a t k o n ta k tn in g y upqa sirtida v u ju d g a keladi. P elte effekti (1 8 3 4 -y ). Ikki m e ta ll o ra s id a Acp k o n ta k t p o te n s ia l la r fa rq i v u ju d g a k e la d i v a b u n d a to k o q m a y d i. T a s h q i e le k tr m a y d o n la r h iso b ig a k o n ta k td a g i p o te n s ia lla r fa rq in i o 'z g a r tir ib , u n d a n to k o q izish m u m k in . D o im iy to k n in g y o 'n a lis h ig a q arab , e le k tro n la r k o n ta k t s o h a sid a k o n ta k t p o te n s ia lla r farq i h iso b ig a y o k i te z la s h a d i, y o k i s e k in la s h a d i (e le k tr e n e rg iy a n i y u ta d i y o k i e le k tr m a y d o n g a e n e rg iy a b e ra d i). T e z la s h g a n e le k tr o n la r k o n ta k tn i so v ita d i, s e k in - la sh g a n e le k tr o n la r k o n ta k tn i isita d i. B u h o d is a d a n k ic h ik e le k tro n p rib o rla rn i so v itish yoki isitish u c h u n fo y d a la n ish m u m k in . k ic h ik b o 'lg a n i u c h u n P e lte effektiga a so sla n g a n isitkich y o k ’ s o v itk ic h n in g q u w a ti k a tta b o 'l m a y d i, le k in u n in g tu z ilis h in in g s o d d a lig i (ik k i s im n in g k o n ta k ti) u n in g q o 'lla n is h ig a s a b a b b o 'la d i. Z e e b a k e ffe k ti ( 1 8 2 1 -y ). T u rli m e ta ld a n y a s a lg a n ikki s im n in g u c h la r i b irla s h tirilib , y o p iq h a lq a h o sil q ilg a n b o 'l s i n , b u n d a y y o p iq z a n jir te r m o p a r a d e b n o m la n a d i. T e r m o p a r a s im ia n o ra s id a k o n ta k t p o te n s ia lla r fa rq i v u ju d g a k e la d i, le k in to k o q m a y d i. A g a r k o n ta k tla r tu rli te m p e r a tu r a d a tu r s a , tu rli k o n ta k tla r d a v u ju d g a k e la y o tg a n p o te n s ia lla r fa rq i s o n j i h a t d a n fa rq la n ib , z a n jir d a e le k tr y u ritu v c h i k u c h v u ju d g a k e la d i va to k o q a b o s h la y d i. K o n ta k t p o te n s ia lla r f a r q in in g te m p e r a tu r a g a b o g 'liq lig in i (5 8 .2 ) f o r m u la d a n k o 'ris h m u m k in . T e r m o p a ra d a v u ju d g a k e la d ig a n E Y U K (te r- m o E Y U K ) te m p e r a t u r a l a r fa rq ig a m u to n o s ib d ir: Е = а { Т 2 - Т {). (58.4) Z e e b a k d o im iy si a m e ta lla rn in g tu rig a b o g 'liq d ir. a m a ’lu m b o 'ls a , Z e e b a k e ffe k tid a n te m io p a ra n in g ikki k o n ta k tid a g i te m p e r a tu ra la r farqini k a tta an iq lik d a o 'lc h a s h u c h u n foy d alan ish m u m k in . B u n in g u c h u n te rm o p a ra d a g i to k n i o 'lc h a s h a sb o b in i s h k a la sig a t e m p e ra tu ra la r fa rq in i belg ilab c h iq is h , y a a n i g ra d u iro v k a qili z a ru r. T e r m o p a r a d a g i to k n in g y o 'n a li s h i t e r m o p a r a u c h l a r i d a g i te m p e ra tu ra la r farqini k a m ay tirish g a h a ra k a t q ilad i: issiq k o n ta k td a issiq lik y u tila d i, sov u q k o n ta k td a issiqlik ajra lib c h iq a d i (P e lte effek ti), issiq lik e le k tr to k i b ila n issiq k o n ta k td a n so v u q k o n ta k tg a tash ilad i. S a v o l va m a s a la la r 58.1. Elektronlarning m etaldan chiqish ishi deb nim aga aytiladi? 58.2. Ichki va tashqi kontakt potensiallar farqi deb nimaga aytiladi? 58.3. T erm o EY U K nimalarga bog‘liq? 58.4. Term oparaning graduirovkasi deb nimaga aytiladi? 5 9 - § . T e r m o e l e k t o n e m i s s i y a v a e l e k t r o n l a m p a l a r M e ta lld a g i e rk in e le k tro n la r y o ru g 'lik fo to n la rin i y u tib , m e ta ll s irtid a n c h iq ib k etish i m u m k in , b u h o d is a fo to e ffe k t d e b a ta la d i. F o to n e n e rg iy a si ha> b u ja r a y o n d a e le k tr o n n i m e ta lld a n c h iq is h ishi ecp ga va e le k tro n n in g n atijaviy E k k in etik energiyasiga sarflanad i: hco = ecp + E k . (59.1) F o to n e n e rg iy asi k a m a y g a n i sari E k h a m k a m a y ib b o ra d i va n ih o y a t fo to e ffe k tn in g qizil c h e g a ra s id a fo to n n in g energ iy asi fa q a t c h iq is h ish ig a etad i: h a q = ecp C h a s to ta со b u n d a n k ic h ik b o 'ls a , fo to e ffe k t k u z a tilm a y d i. F o to e ffe k tn in g b u n d a y tu s h u n tir ilis h i A .E y n s h te y n g a (1 9 0 5 - yil) te g ish li b o 'lib , b u n d a o lim h o d is a n i b irin c h i m a rta y o ru g 'lik k v a n tla ri h a q id a g i ta s a w u r la r a s o s id a tu s h u n tir g a n , a y n a n sh u ishi u c h u n N o b e l m u k o fo tin in g s o v rin d o ri b o 'lg a n . S h u n d a y q ilib fo to e ffe k tn in g x o ssa la ri b ir ta ra fd a n fo to n la m in g m a v ju d lig in i is b o tla s a , ik k in c h i t o m o n d a n e le k tr o n la rn in g m e ta ld a n c h iq is h ish in i o 'lc h a s h im k o n in i b e ra d i. K lassik t a s a w u r l a r b o 'y ic h a m e ta ld a g i e rk in e le k tr o n la r g a z m o le k u la la ri kabi issiq lik h a ra k a tid a b o 'lg a n , M ak svell ta q s im o tig a b o 'y s u n a d ig a n z a rra c h a la r sistem asid ir. M aksvell ta q sim o ti b o 'y ic h a e le k tr o n la rn i o ra s id a o z m iq d o r d a m e ta lld a n c h iq is h e n e rg iy a sig a ega b o 'lg a n e le k tr o n la r h a m u c h ra y d i v a u la r m e ta lld a n c h iq ib ketadi. B u ja ra y o n term oelektron em issiya d eb atala d i. T e rm o e le k tro n e m is s iy a n in g in te n siv lig i b ir ta ra fd a n c h iq is h ish ig a b o g 'liq b o 'ls a , ik k in c h i ta r a f d a n te m p e r a tu r a g a b o g 'liq : in te n s iv lik o rtis h i u c h u n te m p e r a tu ra y u q o riro q , c h iq is h ishi k ic h ik ro q b o 'lis h i kerak. L ekin o d a td a g i te m p e r a tu r a la r d a (300 ) e m issiy a in te n siv lig i s h u n c h a lik k ic h ik b o 'la d ik i, h o d is a n i se z ish m u m k in b o 'lm a y d i. h o d is a n i se z ish u c h u n m a h s u s s h a r o it k erak : • E le k tro n n in g c h iq is h ishi k ic h ik ro q b o 'lg a n m e ta ll; • Y u q o ri te m p e r a tu r a ; • M e t a ll d a n c h iq q a n e le k tr o n la r n i n g u n d a n u z o q l a s h i s h i u c h u n s h a ro it. M e ta lla r o r a s id a se z iy e le k tr o n la rn in g c h iq is h ish i k ic h ik lig i b ila n a jra lib tu ra d i v a e le k tr o n ik a d a q o 'lla n ila d i. K o 'p h o lla rd a p o 'l a t , n ix ro m k a b i o 'tk a z g ic h la r n in g sirti n o d i r m e ta ll b o 'lg a n sez iy b ila n q o p la n a d i. M e ta lln i q iz d iris h u c h u n u n d a n e le k tr to k i o 'tk a z ilib , Jo u l issiqligi b ila n q iz d irila d i. E m issiy a e le k tro n la rin in g e r k in h a r a k a t l a n i s h i u c h u n m e ta ll v a k u u m li s h is h a k o lb a g a jo y la s h tir ila d i, v a k u u m k o lb a d a g i h a v o n i m a x s u s n a s o s la r b ila n s o 'rib hosil q ilin ad i. B u n d a y a sb o b 1905-yilda J .F le m in g to m o n id a n « o 'z g a ru v c h a n to k n i d o im iy to k k a a y la n tiru v c h i a sb o b » n o m i b ila n y aratilg a n va e le k tro n ik a asrin in g p o y q a d a m i b o 'lg a n , hozirgi p a y td a e le k tr o n la m p a , y o k i e le k tr o v a - k u u m l i d io d d e b a t a l a d i ( 5 9 .1 - — i I i h t i r o c h i T . E d i s s o n t o m o n i d a n k a s h f e tilg a n . L e k in E d is s o n b u ra s m ). T e r m o e le k tro n e m iss iy a b u y u k r— h o d is a a h a m iy a tin i y e ta rli a n g la - L b o 'l g a n i h o l d a , e m is s iy a h o d is a s ig a p a t e n t o l m a g a n . L e k in te rm o e le k tr o n e m issiy a h o d isa s i b a ’z a n u n in g ism i b ila n « E d isso n effekti» d e b a ta la d i. T e r m o e le k tro n e m is siy a h o d is a s in i n a z a riy ji h a t d a n O .R ic h a r d s o n (19 0 2 ) o 'r g a n ib c h iq d i. Z a rra la rn i te z lik la r b o 'y ic h a M a k sv e ll ta q s im o tig a a s o s a n , R ic h a r d s o n e n e rg iy a s i c h iq is h is h id a n k a tta b o 'lg a n e le k tr o n la r s o n in i s ta tis tik h is o b la b , q u y id ag i n a tija g a kelg an : j = A T 2 exp(-e< p/ k T ) . (59.2) Bu y e rd a j — em issiy a e le k tro n la rin in g to k z ic h lig i, ecp — e le k tro n la rn in g c h iq is h ish i, A — d o im iy k o e ffitsiy e n t. S .D e s h m a n (5 9 .2 ) fo r m u la k v an t fizik a si n u q ta i n a z a rid a n h a m to 'g 'r ilig in i ta s d iq la b , A = 120/1 / sm 2K 2 k o e ffitsiy e n tn i n a z a riy h is o b la g a n , s h u n in g u c h u n fo rm u la R ic h a rd s o n D e s h m a n fo r m u la s i d e b a ta la d i. C h iq is h ish i ecp = 1.97eK (ts e z iy n in g p a r a - m e tr i) , t e m p e r a t u r a T = ЗООЛ" d e s a k , R ic h a r d s o n D e s h m a n fo r m u la s ig a k o 'r a j = ю ~2b A / sm 2 (b u n a tija g a k o 'r a 1 s m 2 s irtd a n 107 s d a v r d a b i t t a e le k tr o n c h iq is h i k e ra k ). E m is s iy a m a t e r ia li - n in g t e m p e r a tu r a s i n i 1300ЛГ ga y e tk a z s a k , e m is s iy a to k z ic h lig i j = 4 .7A/sm2 g a y etad i, te m p e ra tu ra n in g 4— 5 m a rta o sh ish i n atijasid a e m is s iy a 26 ta rtib g a o s h d i. D e m a k , e m issiy a to k la rid a n te x n ik a d a f o y d a la n is h m u m k in b o 'l is h i u c h u n e m is s iy a m a n b a i a lb a tta qizdirilishi k erak ekan. S h u n g a o 'h s h a b , em issiya intensivligi ch iq ish is h in in g q iy m a tig a h a m k u c h li b o g 'liq d ir. ( R ic h a r d s o n — D e s h m a n fo rm u la si y a n a y a r im o 'tk a z g ic h - lardag i te m p e r a tu ra bilan b o g 'liq o 'tk a z u v c h a n lik e le k tro n la r so n in i h is o b la s h d a h a m q o 'lla n ila d i. B u n in g s a b a b i s h u n d a k i, o 'tk a z u v c h a n lik e le k tr o n la r n in g s o n i h a m , te r m o e le k tr o n la r so n i h a m a so siy z o n a d a g i e le k tr o n la rn in g b ir q ism i — e n g k a tta e n e rg iy a lik e le k tr o n la r n in g b ir h o ld a c h iq is h ish in i b a ja rib , b o s h q a h o ld a ta q iq la n g a n z o n a n i s a k ra b o 't i s h b ila n y u q o ri e n e rg iy a lik h o la tg a o 'tis h i b ila n b o g 'liq . B ir-b irig a o 'h s h a s h s ta tis tik m a s a la la r b ir y e c h im g a k e ltirila d i.) E le k tro v a k u u m li d io d b ir ta ra fd a n e le k tro n e m is s iy a n i o 'r g a n ish v o s ita s i b o 'l s a , ik k in c h i ta r a f d a n e le k tro n e m is s iy a n i q o 'lla - n i s h i d i r . D a s t l a b e m is s i y a n in g l a m p a d a g i k u c h l a n i s h U g a 2 7 4 b o g 'la n is h in i ta h lil etay lik . E le k tro n la m p a elek tr s x e m a d a 5 9.1-ra sm d a g i k a b i b e lg ila n g a n b o 'l s a d a , k o n s - tr u k tiv jih a td a n b o s h q a c h a y asaladi. M a s a la n , e m i t te r ta r a n g to rtilg a n v a to k o 'tk a z ib q iz d irila y o tg a n s im - d a n ib o ra t b o 'la d i. E m itte rn i q iz d i- ru v c h i to k n i o s h ir ib , a n o d to k in i o s h iris h m u m k in . E m is s io n e le k tr o n la r n in g y e tib b o ris h i y e n g ilro q b o 'lis h i u c h u n k o ll e k to r e m itte rn i o 'r a b tu ru v c h i s ilin d r s h a k lid a y a sa la d i. S ilin d r n in g ra d iu s i k ic h ik ro q b o 'ls a , o r tiq r o q e m is s io n to k k a e r is h i s h m u m k in . A n o d to k i n in g ta s h q i k u c h l a n i s h g a b o g 'la n is h i ( 5 9 .2 - r a s m ) d io d n in g v o lt a m p e r x a ra k te ris tik a s i dey ilad i. T a s h q i q a r s h ilik c h e k s iz k a tta b o 'ls a (y o k i ta s h q i z a n jir u z ib q o 'y ils a ) a n o d to k i n o lg a a y la n ib , e le k tr o n la r c h iq a r g a n e m i t te r m u s b a t, e le k tr o n la r n i q a b u l q ilg a n k o lle k to r m a n fiy z a ry a d la n ib q o la d i, u la r o r a s id a d o im iy , q iy m a ti e m it te r h a r o r a tig a b o g i i q b o 'lg a n k u c h la n is h h o sil b o 'la d i. B u k u c h la n is h to k n i b e k itu v c h i k u c h la n ish d eb a ta la d i. T a sh q i q a rsh ilik n i k a m a y tirib b o rsa k , ta sh q i z a n jird a O m q o n u n ig a k o 'r a to k (a n o d to k i) p a y d o b o 'la d i, e m itte r va k o lle k to r o ra sid a g i to k k a to 's q in lik q ilu v ch i k u c h la n ish k a m a y ib , u la r o ra s id a e m is siy a e le k tro n la rin in g o q im i p a y d o b o 'la d i. B u to k 5 9 .2 -ra sm d a k o o rd in a ta b o s h id a n c h a p d a tasv irlan g a n . Z a n jir d a h o s il b o 'l g a n to k b ir o r m a q s a d d a f o y d a la n ilis h i m u m k in . D e m a k e le k tro n em issiya vositasida bironta h ara ka tla n u vch i q ism la ri b o 'lm a g a n to k m a n b a i y a ra tilis h i m u m k in e k a n . U n d a e m itte rn i q iz d iris h u c h u n s a rfla n g a n is siq lik e n e rg iy a si t o 'g 'r i d a n t o 'g 'r i e le k tr e n e r g iy a s ig a , e le k tr to k ig a a y la n tir ila d i. B u n d a y q u rilm a te r m o e m is s io n to k m a n b a i d eb a ta la d i, u real a h a m iy a tg a eg a b o 'lis h i u c h u n y e ta rli q u w a tg a , fo y d a li ish k o e f its iy e n tig a , iq tso d iy s a m a ra d o rlik k a ega b o 'lish i kerak. T e r m o e l e k t r o n t o k m a n b a in in g h a r a k a t l a n u v c h i q is m la r i b o 'lm a g a n i u c h u n e m itte r n i is itis h , k o lle k to rn i so v itis h a m a lg a o s h g a n d a tin im s iz y illa b ish la s h i m u m k in . M a n b a n in g b u n d a y is h o n c h li b o 'lis h i ay n iq sa k o sm ik s h a ro itd a m u h im a h a m iy a tg a ega va k o sm ik k e m a la rn in g a y r im la r id a te rm o e m is s io n to k m a n b a i q o 'lla n ilg a n . E m itte r u c h u n issiq lik m a n b a i s ifa tid a ra d io a k tiv m o d d a q o 'lla n ilg a n , k o lle k to r k o sm ik k e m a n in g so y a ta ra fid a jo y la s h ib , fa z o g a issiq lik e le k tr o m a g n it t o 'l q i n la r i n i c h iq a r ib , so v itilg a n (k o s m ik fa z o n in g te m p e r a tu ra s i re lik t n u rla n is h b ila n belgilanadi v a 2.3K ga teng). K elajakda em ittern i k o 'z g u la r y o rd a m id a y ig 'ilg a n Q u y o s h n u rla ri y o rd a m id a isitish re ja la ri b o r , b u n d a e le k tr e n e rg iy a Q u y o sh n u rla ri e n e rg iy a s i h is o b ig a y a ra tila d i. Q u y o s h d o im iy isi S = 1.3 k W / m 1 P o y tin g v e k to rin in g m o d u - lid a n ib o ra t b o 'l ib , b irlik y u z a g a tu s h a y o tg a n Q u y o s h n u r la n is h i- n in g q u w a t i n i n g b ild ira d i. A tm o sfe ra b u q u w a tn in g b ir q is m in i a k s la n tiris h i va y u tish i h iso b ig a Y e r s irtid a q u y o s h d o im iy i k a m a y a d i. K o s m o s d a esa b u n d a y c h e k lo v y o 'q . E m itte r v a k o lle k to r s irtin i o s h ir ib ix tiy o riy k a tta Q u y o s h q u w a ti n i y ig 'is h m u m k in . T e rm o e m is s io n to k m a n b a in in g k o sm o sd a q o 'lla n ilish in i q u lay to m o n i s h u n d a n ib o ra tk i, e m itte r va k o lle k to r o ra sid a g i v a k u u m u e rd a ta b iiy , v a k u u m n i u s h la b tu ru v c h i n o z ik v a o g 'i r s h is h a id ish k e ra k e m a s (d e m a k e m itte r va k o lle k to r s irtla rin i j u d a k a tta q ilish m u m k in ) , n a s o s la r y o r d a m id a h a v o n i s o 'r i b o lis h h a m z a r u r e m a s . Q u y o s h e n e rg iy a s id a n e le k tr o lis h u c h u n f o to e f fe k td a n h a m f o y d a la n is h m u m k in . M a s a la n , E — 2 E Y U K h o sil q ilin m o q c h i, e le k tr o n la rn in g c h iq is h p o te n s ia li — 1 K b o 'ls in . U n d a c h a s to ta s i h v > 3 eV s h a r tn i q a n o a tla n tiru v c h i f o to n la r e le k tr o n la rn i e m it- te rd a n k o lle k to rg a o 'tk a z ib , to k m a n b a ig a hissa q o 's h is h i m u m k in . B u n in g u c h u n e m itte r va k o lle k to r o 'z a r o p a ra lle l v a y a q in jo y la - s h i s h i, t e r m o e le k tr o n e m is s iy a k u z a tila d ig a n s h a r o itg a o 'x s h a b , М П а- e m *t t e r v a k o l l e k t o r o r a s i d a v a k u u m b o 'lis h i k erak . K o lle k to r s h a f f o f b o 'l i b , n u r i a r k o lle k to r Firitic- o r c la l* e m itte rg a tu s h ib , fo to e ffe k t h o s il q ils a , m a q s a d g a m u v o fiq 59.3-rasm. b o 'la d i (5 9 .3 -ra s m ). F o to e f f e k tn in g c h e g a r a v iy t o 'l q i n u z u n l i g i n i h is o b la s a k : X = c / v < c h / l e V = 400/7/и . Y a ’n i Q u y o s h n u rla n is h id a g i b u tu n y o ru g 'lik va u ltr a b in a f s h a n u ria r , n u rla n is h e n e rg iy a s in in g a s o s iy q ism i to k m a n b a ig a h issa q o 's h is h i m u m k in va u n in g F I K j u d a y u q o ri, m a s a la n , 50% b o 'li s h i m u m k in . I n t e r n e t d a c h iq is h ish i y u q o rid a g i h is o b d a q o 'll a n il g a n l e V d a n h a m k ic h k in a , 0 .4 e K b o 'l g a n n a n o u g le r o d m a te r ia li h a q id a m a ’lu m o t to p is h m u m k in . B u n d a y m a te ria l in fra q iz il n u r ia r e n e rg iy a s in in g k a tta q is m in i h a m elek tr en e ig iy asig a a y lan tirish g a x iz m a t qilishi m u m k in . B u n d a y fo to e le k trik q u rilm a la rd a y u q o ri te m p e r a tu r a g a h a m z a r u r a t y o 'q . O 'q u v c h ig a tu s h u n tir is h n u q ta i n a z a r id a n , te r m o e le k tr o n to k m a n b a in i b irin c h i b o 'lib b a y o n etdik. L ek in ta rix a n ele k tro v a k u u m li d io d b o sh q a m u h im v a z ifa la m i b ajarg an . T a sh q i k u c h la n ish m a n b a i v o sita sid a d io d n in g e m itte r ig a m a n fiy , k o lle k to rig a m u s b a t k u c h la n is h b e rilsa , b u a n o d to k in in g o sh is h ig a o lib k elad i (5 9 .2 -ra s m d a k o o r d in a ta b o s h id a n o 'n g ta ra f). E m itte r te m p e r a tu r a s i d o im iy b o 'lg a n i h o ld a to k k u c h i k u c h la n is h g a q u y id a g ic h a b o g 'liq e k a n : I = C U 2/ 2 . (59.3) Bu yerd a С elek tro d la rn in g shakli va o 'lc h a m la ri, e m itte r m a te ria lig a b o g 'liq b o 'lg a n d o im iy . B u n d a y b o g 'la n is h B o g u sla v sk iy — L e n g - m y u r q o n u n i, y o k i 3 /2 q o n u n i d eb a ta la d i. K u c h la n is h n in g k a tta q iy m a tla rid a to k n in g to 'y in is h i k u z a tila d i. T o k n i k u c h la n ish g a b u n d a y b o g 'la n is h in i q u y id a g ic h a iz o h la sh m u m k in . T a s h q i k u c h la n i s h b o 'l m a g a n i d a , e m is s iy a q ilg a n e le k tr o n la rn in g b i r q is m ig in a k o lle k to rg a b o rib y e ta d i. T a s h q i (m u sb a t) k u c h la n ish k o lle k to ig a b o rib e ta d ig a n em issiy a e le k tro n la rin in g s o n in i o s h ira d i. T a s h q i k u c h la n is h n in g k a tta q iy m a tla r id a e m issiy a e le k tr o n la rin in g b a rc h a s i k o lle k to rg a b o rib y e tib , a n o d to k in in g to 'y in is h i k u z a tila d i. T o 'y in is h to k in in g q iy m a ti e m i t te r te m p e ra tu ra s ig a va sirtig a R ic h a rd s o n — D e s h m a n fo rm u la s i b ila n b o g 'liq d ir. E le k tro v a k u u m li d io d g a m u s b a t k u c h la n is h b e r ilg a n d a to k o 'tk a z a d i, m a n fiy k u c h la n is h b e rilg a n d a to k o 'tk a z m a y d i. S h u n in g u c h u n u n in g d a s tla b k i q o 'lla n is h i — « o 'z g a ru v c h a n to k n i d o im iy to k k a a y la n tiris h » d a n ib o ra t b o 'lg a n . E le k tro v a k u u m li d io d g a , e m i t t e r v a k o lle k to r o ra s ig a m e ta ll t o 'r k ir itib , a n o d t o k in i b o s h q a r u v c h i k u c h li v o sita h o sil q ilin a d i. B u n d a y q u r ilm a u c h e le k tr o d li la m p a d e b n o m la n a d i. T o ‘r te s h ik b o 'lg a n i u c h u n e m itte r d a n c h iq q a n e le k tr o n la rn in g o z q is m i u n g a tu s h a d i, a so s iy q ism i ilg arig id ek , k o lle k to rg a b o rib e ta d i. L e k in t o ‘r e m itte rg a y a q in ro q tu rg a n i u c h u n , u n g a b e rilg a n m u s b a t k u c h la n is h a n o d to k in i o s h ir a d i, m a n fiy k u c h la n is h a n o d to k in i k a m a y tir a d i, t o ‘rn in g k u c h la n is h in i a n o d to k in in g q iy m a tig a t a ’siri e m i t te r v a k o lle k to r o ra s id a g i k u c h la n is h g a n is b a ta n a h a m iy a tliro q b o ‘lib q o la d i. T o 'ig a k u c h siz sig n a lla m i u la b (m a s a la n a n te n n a v o sita sid a tu tilg a n e le k tr o m a g n it t o 'l q in la m i) , a n o d to k in in g k u c h li o 'z g a r i- sh ig a erish ish m u m k in . S h u n d a y qilib , u c h elek tro d li la m p a k u c h siz s ig n a lla rn i k u c h a y tiru v c h i e le m e n t b o ‘lib x iz m a t q ilad i. U c h elek tro d li la m p a n in g y a ra tilis h i e le k tro n ik a asrin i b o sh la b b e rd i. R a d io , te le v id e n iy e , tu rli a lo q a v o s ita la ri, ra d io lo k a ts iy a , n ih o y a t k o m p y u te rla r n in g d a stla b k i tu rla ri b a y o n e tilg a n e le k tr o n la m p a la rg a a s o s la n g a n ed i. Y a rim o 'tk a z g ic h li d io d v a tra n z is to r la r u la m in g v az ifasin i b a ja ru v c h i ix c h a m va e n e rg iy an i te jo v c h i keyingi a v lo d e le k tr o n q u r ilm a la r i b o ‘ld i. Y a r im o 'tk a z g i c h l i d i o d va tra n z ito r la r n i in te g ra l sx e m a la rd a y a ra tila b o s h la s h i b ila n e le k tro n a s b o b la rn in g riv o jla n ish in in g z a m o n a v iy p o g 'o n a s i b o s h la n d i. B ir in te g ra l s x e m a d a b a ’z a n m illia r d d a n o rtiq e le k tro n e le m e n tla r y a ra tila d i. Z a m o n a v iy e le k tro n ik a y u tu q la rin i b u y erd a b a y o n etish u c h u n jo y y e tm a y d i. S a v o l va m a s a la la r 59.1. R ichardson-D eshm an formulasi nim ani ifodalaydi? 59.2. Fotoeflektdan tok m anbai hosil qilish uchun qanday foydalanish m um kin? 59.3. U ch elektrodli lam paning elektron lam padan farqi nim ada? 6 0 - § . О Ч а о ‘t k a z u v c h a n l i k O 't a o 'tk a z u v c h a n lik ( 0 ' 0 ‘) ta b ia tn in g n o d ir h o d is a s i b o 'lib , p a s t h a r o r a td a o d d iy m e ta ll e le k tr q a rs h ilig i n o lg a a y la n is h i, o 'tk a z u v c h a n lig i c h e k s iz b o 'lib q o lis h id a n ib o ra t. O 'O ' h o la tig a o ‘tis h te m p e r a tu ra s i Tk — k ritik te m p e r a tu r a d e b a ta la d i v a 0 ‘0 ‘ n in g m u h im x a ra k te ris tik a s i h is o b la n a d i. Y u q o ri te m p e r a tu r a d a m o d d a o d d iy h o la td a b o 'l s a ( m e ta ll, y a r im o 't k a z g i c h , h a t t o d ie le k trik ), te m p e r a tu r a k ritik te m p e r a tu r a d a n p a s a y g a n d a o 't a o 'tk a z u v c h a n h o la tg a o 'tis h i k u za tilad i. M o d d a n in g e le k tr x ossalari o 'z g a ris h i b ila n b irg a issiq lik s ig 'im i, m a g n it v a b o s h q a x o ssa la ri h a m o 'z g a ra d i. T e rm o d in a m ik a n u q ta i n a z a rid a n bu ik k in ch i tu rd ag i (issiq lik y u tilm a s d a n r o 'y b e r a d ig a n ) fa z o v iy o 'tis h d ir . O 'ta o 'tk a z u v c h a n lik hodisasi b irin c h i b o rg o lla n d fizigi K a m e r- lin g — O n n e s to m o n id a n 1 9 1 1-yili k u z a tilg a n edi. Bu o lim g a z la m i s u y u ltir is h d a m u v a ffa q iy a tg a e rish g a n lig i b ila n m a s h h u r. B irin c h i b o r g e liy g a z in i s u y u ltirg a n o lim , s u y u q g e liy y o rd a m id a b e n ih o y a p a s t h a r o ra tla rn i h o s il q ilish g a e ris h d i. S h u b ila n b irg a o lim la r o ra s id a b irin c h i b o 'lib b u n d a y p a s t, a b so ly u t n o lg a y aq in h a r o ra td a m o d d a xossalarini o 'lg a n is h im koniyatiga ega b o 'ld i. Past haro ratlard a s im o b q a r s h ilig in i o 'r g a n a y o t i b , K a m e r lin g — O n n e s 4 .1 5 K te m p e r a tu r a d a q a r s h ilik n in g sa k ra b k a m a y is h in i k u z a tg a n o lim , b u n i sim o b n in g y an g i h o la tg a o 'tis h i b ila n tu s h u n tir d i ( 6 0 .1 -ra sm ). B u h o la tn in g a so siy x a ra k te ris tik a s i — e le k tr q a r s h ilik n in g n o lg a a y la n is h id a n ib o ra t, b u n d a y o 'z g a r is h r o 'y b e r a d ig a n h a r o r a tn i T k - k ritik te m p e r a tu r a d e y ila d i. B u h a r o r a td a m o d d a n in g issiq lik s ig 'im i h a m k eskin o 'z g a r a d i (ra sm d a g i ik k in c h i g ra fik k a q a ra n g ). K e y in c h a lik iz la n is h la r b u h o d is a b o s h q a m e ta lla rd a , m e ta lla rn in g q o tis h m a la rid a , a y rim y a r im o 'tk a z g ic h la rd a , p o lim e rla rd a , h a tto k i o d a td a g i h o la td a d ie le k trik b o 'l g a n k e ra m ik m o d d a la r d a h a m k u z a tilg a n . A y rim m o d d a la r n in g k ritik h a r o ra ti q u y id a g i ja d v a ld a k e ltirilg a n . Download 48 Kb. Do'stlaringiz bilan baham: 
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