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BI 16DNG IN TRONGCHN KHNG

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Ni dung Cch to dng in trong chn khngI Tia CattII

Cch to dng in trong chn khngI1) Bn cht dng in trong chn khng2) Th nghim

Dng in l dng chuyn di c hng ca cc ht mang in

Cch to dng in trong chn khngI

C cc ht mang in t doC in trng ngoiDng in l g ?

iu kin to dng in trong mi trng bt k l g ?

Mi trng chn khng l mi trng nh th no?N c dn in khng ? Ht ti in l cc ion v electron c c do qu trnh ion ha

Ht ti in l cc ion c c do qu trnh phn ly

Cch to dng in trong chn khngIC cc ht mang in t doHt ti in l electron t do c sn trong kim loi

KIM LOICHT IN PHNCHT KHChn khng l mi trng c ly i cc phn t kh. N khng cha cc ht ti in nn khng dn inTa phi a cc electron vo trong khong chn khng n c th dn in

Vy th lm sao to ra cc ht ti in?

-+

Cch to dng in trong chn khngI1.Bn cht dng in trong chn khngDng in trong chn khng l dng chuyn di c hng ca cc electron c a vo khong chn khng .

E

IC cc ht mang in t dot vo mt in trng ngoi

L ht ti in trong mi trng chn khngVy, ta a electron vo trong nh th no ?

Cch to dng in trong chn khngI2.Th nghim

AKV*S CATT K (-)ANT A (+)*THC HIN-Tin hnh t nng catt cc mc khc nhau, cho hiu in th UAK gia ant v catt thay i gi tr t m n gi tr dng , a ra nhn xt v v biu .

Ta a electron vo bng cch t nng catt ca bng chn khng.

Cch to dng in trong chn khngI2.Th nghim*KT QU

IUO

T2 > T1a) T0

c) T2Ibh2

b) T1Ibh1 th a): Khi K khng c t nng, I = 0

th b): Khi K nng :+ UAK < 0: I khng ng k+ UAK > 0: I tng nhanh theo U ri t gi tr bo ha th c): t dy tc vi nhit cao hn, ng cong (c) c dng nh (b) nhng dng bo ha ln hn0

Dng in trong chn khngkhng tun theo nh lut OhmDng bo ha Dng in trong chn khng c tun theo nh lut Ohm khng?

Cch to dng in trong chn khngI2.Th nghim*Gii thch

-Khi UAK m v nh, cc lectron c tc ban u ln vn thng c lc y ca ant v ti ant, gy ra mt dng ant nh chy v catt-Khi UAK dng, ant ht cc lectrn v gy ra dng ant ln-Khi s electrn pht ra t mt giy bng s electrn n ant trong mt giy th dng in t n gi tr bo ha. V th, nhit catt cng cao, dng bo ha cng ln

Tia CattII1) Th nghim2) Tnh cht tia catt3) Bn cht tia catt4) ng dng

Tia CattII

1.Th nghim*Dng c*Th ngim to ra dng in trong chn khng bng cch rt dn kh trong:-ng thy tinh di chng 30cm -Ngun in c hiu in th vi ngn vn

Tia CattII1.Th nghim*Tin hnh th nghimKA

-Khi p sut ca kh trong ng bng p sut kh quyn, ta khng thy qu trnh phng in.p sut bn trong ng = p sut kh quyn

Off

Tia CattII1.Th nghim*Tin hnh th nghim-Khi p sut nh, trong ng c qu trnh phng in t lc, trong ng c mt ct kh pht sng ko di t ant n gn catt (ct sng ant), cn gn catt c mt khong ti (khong ti catt)

ON

Tin hnh rt khng kh trong ng ra ngoiKATrong ng xut hin ct kh pht sng v mt khong tiCu hi C2

Off

Tia CattII1.Th nghim*Tin hnh th nghim

ON

- - - - - - - - - - - - - - - - - Khi p sut trong ng =10-3 mmHg khong ti catt m rng chim ton b ng, thnh thy tinh pht sng mu vng lcKA

-Khi p sut trong ng h xung cn khong 10-3 mmHg, khong ti catt m rng v chim ton b ng. Qu trnh phng in vn duy tr pha i din catt, thnh thy tinh pht nh sng mu vng lc.-Ta gi tia pht ra t catt lm hunh quang thy tinh l tia catt-Tip tc ht kh t chn khng tt hn na th qu trnh phng in bin mtCu hi C3

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Tia CattII2.Tnh cht tia catt

Tia CattII2.Tnh cht tia catt*Tia catt pht ra t catt theo phng vung gc vi b mt catt. Gp mt vt cn n s b chn li lm vt tch in m

K A- +

--

Ht kh

Tia CattII2.Tnh cht tia catt*Tia catt mang nng lng ln: n c th lm en phim nh, lm hunh quanh mt s tinh th, lm kim loi pht ra tia X, lm nng cc vt m n ri vo v tc dng lc ln n

K A- +

Ht kh

Tia CattII2.Tnh cht tia catt*Tia catt b lch trong in trng v t trng

K A- +

Ht kh

Tia CattII3.Bn cht ca tia catt

*Tia catt l mt dng cc electron pht ra t catt , c nng lng ln v bay t do trong khng gian.

Tia CattII4.ng dng ca tia catt

*ng phng in t, n hnh (CRT)

Tia CattII4.ng dng ca tia catt*ng in t, n hnh (CRT)Cch hot ng ca n hnh trong TV CRT

Tia CattII4.ng dng ca tia catt*n chn khng

Tia CattII4.ng dng ca tia catt*Dng chn on bnh trong y t (to ra tia X)

*Kin thc cn nh chn khng dn in ta phi a cc electron vo trong (ht ti in trong mi trng chn khng l cc electron a t bn ngoi vo)

Dng in trong chn khng l dng chuyn di c hng ca cc electron c a vo khong chn khng .

*Tnh cht tia cattTia catt pht ra t catt theo phng vung gc vi b mt catt. Gp mt vt cn n s b chn li lm vt tch in mTia catt mang nng lng ln: n c th lm en phim nh, lm hunh quanh mt s tinh th, lm kim loi pht ra tia X, lm nng cc vt m n ri vo v tc dng lc ln n.Tia catt b lch trong in trng v t trng.

Bn cht ca tia catt l mt dng cc electron pht ra t catt , c nng lng ln v bay t do trong khng gian.ng dng ch yu ca tia catt l lm ng phng in t, n hnh.

*Cng c bi hc4132

Cu 1in vo ch trng hon thnh cu sau vi 3 t cho trc bn di:

Dng in trong . . . l dng chuyn di c hng ca cc . . . c . . . khong chn khng

chn khnga voelectron

Cu 2Ngi ta kt lun tia catt l dng ht tch in m v ?A. N c mang nng lngB. Khi gi vo vt no n lm vt tch in mC. N b in trng lm lch hngD. N lm hunh quang thy tinh! Sai ri!

Wow! ng ri

Cu 3Trong 30 giy, bn phi tm ra t c 8 ch ci thng qua cc nh gi di y!

T I A C A T T

Ht giChc mng bn chn c cu hi may mn!

Cu 4Hon thnh bng tm tt v dng in trong cc mi trng di y:MTHt ti inBn chtKim loiElectron t doDng in trong kim loi l dng chuyn di c hng ca cc electron t do di tc ng ca in trngCht in phnIon dng v ion mCht khElectron c to nh tc nhn ion haDng in trong cht kh l dng chuyn ng c hng ca cc electron v cc ion trong in trngChn khngDng in trong chn khng l dng chuyn ng c hng ca cc electron c a vo khong chn khng

Dng in trong cht in phn l dng chuyn di c hng ca cc ion trong in trngElectron a vo

Chc mng bn chn c cu hi may mn!

Cm n c v cc bn ch lng nghe!

THE END!

Tr li : V iu kin bnh thng khng kh l in mi. Khi p sut nh ch mt t l rt nh cc lectron va chm vi cc phn t kh lm ion ha chng. Cc ion dng nhn nng lng ca in trng p vo catt, sinh ra cc electron mi duy tr qu trnh phng inHi : Trong th nghim trn, v sao khi p sut cn ln ta khng thy qu trnh phng in qua kh v khi p sut nh li c qu trnh phng in t lc ?Cu hi C2(Sgk/97)