NI DUNG N TP THC TP VT L YHCT 2014 - 2015

6NI DUNG N TP THC TP VT L YHCT 2014 - 2015

Cu 1. Cu to thc kp? i lng a, N l g?Cu to thc kp:Thc kp gm 2 phn chnh:Phn c nh A c dng hnh ch T c khc chnh xc ti mm.Phn di ng B: Trt trn thc chnh v hp vi ming thp E thnh 2 hm kp c cnh song song. Trn B c gn mt thc ph (du xch) c di ca mi chia nh hn thc chnh.i lng a l:chiu di ca mi khong chia ca thc chnh Ai lng N l:Tng s vch chia trn thc du xch B.

Cu 2. S khng thc ca thc kp?1. Khi 2 hm E v F tip xc m vch 0 trn thc chnh v vch 0 trn du xch trng nhau th kt qu o khng phi hiu chnh . (S khng thc bng 0) 2.Khi 2 hm E v F tip xc m vch 0 trn thc chnh v vch 0 trn du xch khng trng nhau c 2 trng hp:Nu vch 0 ca du xch bn phi vch 0 ca thc chnh v vch th n ca du xch trng vi mt vch no trn thc chnh th kt qu c phi tr i (mm).Nu vch 0 ca du xch bn tri vch 0 ca thc chnh v vch th n ca du xch trng vi mt vch no trn thc chnh th kt qu c c phi cng thm (mm).

Cu 3. im khng thc ca Palmer?Vn c E cho hai mu A v B tip xc nhau (nghe ting lch cch) 1. Nu mp trng trng vi s 0 ca L1 v s 0 ca L2 trng vi ng chun, th kt qu o khng phi hiu chnh. (S thc bng 0)

2. Ngc li c hai trng hp:Nu mp trng cha ti s 0 ca L1 v vch th n ca L2 trng vi ng chun, th kt qu o phi tr i(mm).Nu mp trng vt qu v tr s 0 L1 v c vch th n ca L2 trng vi ng chun, th kt qu o phi cng thm (mm).

Cu 4. Phng php mao qun?Dng mt ng mao qun c tit din u,nhng vo trong mt chu ng cht lng, s chnh lch ca mc cht lng trong v ngoi ng mao qun tun theo nh lut Jurin. Da vo nh lut ny, ta c cng thc tnh h s cng mt ngoi (SCMN) l:Trong :r: bn knh trong ca ng mao qunh: chnh lch ca cht lng trong v ngoi ng.D: khi lng ring cht lng.Do vic o chnh xc cao ca ct cht lng rt kh khn nn ngi ta thng dng cch o hiu s cao ca ct cht lng ca cc ng c bn knh khc nhau nh sau:Nhng 2 ng mao qun c bn knh r1, r2 vo cht lng, cht lng dng ln vi cc cao h1, h2 tng ng.Ta c:

Cng c th xc nh h s sc cng ca mt cht kho st X bng cch so snh n vi mt cht lng chun (nc ct) c h sc cng bit trc, ngha l:

T : Trong : h0, hx tng ng l cao ct cht lng dng ln ca nc ct v cht lng kho st. D0, Dx tng ng l khi lng ring ca nc ct v cht lng kho st.

Cu 5. Phng php tch vnh kim loi?H s cng mt ngoi c th xc nh bng cch o lc cn thit tch vnh kim loi ra khi mt cht lng.Gi mt vnh kim loi sao cho mt di ca n tip xc vi mt thong ca cht lng. V cht lng lm t vnh nn mt ngoi ca cht lng ch tip xc vi vnh c dng lm. Do tc dng lc cng mt ngoi cht lng s ko vnh xung. ko vnh kim loi ln khi mt cht lng, ngoi lc ko cn bng vi trng lng vnh ta cn phi tc dng thm mt lc ko cn bng vi lc cng mt ngoi nn ta c:F = (2R + 2r) = 2(R+r)Trong :R: bn knh ngoi ca vnh.r: bn knh trong ca vnh.Vy:

Cu 6. nh ngha hin tng nhiu x nh sng? Nu cc yu t gy ra sai s trong vic tin hnh thc nghim?1. Nhiu x nh sng l hin tng cc tia sng b lch khi phng truyn thng khi i qua cc vt cn ( l trn nh, khe h hp, ...)2. Cc yu t gy ra sai s trong vic tin hnh thc nghimo k v tr nh ca cc i chnh bng cch dch chuyn Palmer tng 0.01mm. V ch cn di chuyn Palmer nhanh qu 0.01mm cc v tr ln cn t 2 pha mi nh cc i th trn th nh cc i s t v cho nhiu gi tr x mi nh cc i nn kt qu s khng chnh xc.

Cu 7. Vit cng thc xc nh bc sng laser v cng thc sai s.Nu ngha tng i lng.Cng thc xc nh bc sngca chm laser, ngha cc i lng = d.sini vi cc i chnh bc 1 gc kh nh nn c th coi gn ng: Sin tg = Thay vo cng thc trn ta tm c: = : Bc sng ca chm tia laser.d : Chu k ca cch t phng.f : Tiu c ca thu knh hi t.sin : Gc nhiu x.Cng thc tnh sai s tng i ca php o Cng thc tnh sai s tuyt i ca php o

Cu 8. V sao gia 2 cc tiu chnh s c nhiu cc i chnh?Ta c cng thc sau t s kho st s phn b cng sng gia 2 cc tiu chnh:L = L2 L1 = d.sinNu L = d.sin= k.th dao ng sng do 2 chm tia nhiu x ny (v do cc chm tia nhiu x t cc khe hp khc) ti im M u ng pha vi nhau. Kt qu, im M s sng v c gi l cc i chnh. V tr ca cc cc i chnh c xc nh bi cng thc: Sin= trong k = 0, 1, 2,Vi k = 0, sin = 0 ta c cc i gia nm ti tiu im F ca thu knh hi t L. V d >b nn gia 2 cc tiu chnh s c nhiu cc i chnh.

Cu 9. K tn v nu r bn cht ca cc thnh phn c trong tia phng x ca urani v cc hp cht ca n?Tia phng x ca urani v cc hp cht ca n c tnh cht pht ra nhng tia phng x gm 3 loi: Tia l cc ht nhn bn. Tia l cc electron. Tia l cc bc x in t c bc sng rt ngn.

Cu 10. nh ngha Tc m ? Phng my m ? Nu r cng thc tnh v n v o ca tc m? Trnh by phng php o phng ca my m Geiger - Muller1. Tc m(n) l s xung in m my m ghi c trong mi pht. 2. Cng thc tnh, n v o ca tc m: Vi N l s xung in ghi c trong thi gian t phtn v: xung/pht 3. Phng ca my m l tc m trung bnh ca n khi khng c ngun phng x 4. Phng php o phng ca my m Geiger - Mullera. ng m Geiger - Muller GM c lp trn gi BP. Cm u jack ca ng m GM vo l cm u d pha trn thn my ca my m xung in t.Cm adaptor cp ngun ca my m vo ngun in ~ 220V.b. Gt cng tc chn thang thi gian ca my m xung in t thang 1 Min.Gt cng tc ngun sang v tr ON, mn hnh LCD s sng. Bt n backlight nu thy mn hnh LCD ti.Vn nm chnh phn gii gc trn bn tri thn my cho mn hnh hin th r nt.c. My m s t o s xung in N0 trong khong thi gian t = 60s.c v ghi gi tr ca N0.Thc hin ng tc ny 3 ln tnh gi tr trung bnh v xc nh phng ca my m theo cng thc Ghi ch: C th o s xung in trong thi gian ty chn theo 3 thang ca my : 1 giy, 1 pht, 1 gi bng nt gt chn thang thi gian o.

Cu 11 : Gii thch nguyn l hot ng ca my m Geiger - Muller?Nguyn l hot ng ca my m Geiger-Mullerng m Geiger-Muller l mt t in t trong ng thy tinh c cha in mi l cht kh p sut khong 100mmHg. in cc th nht ca t in tr l mt si dy kim loi. in cc th hai l mt lp dn in ph ln mt trong ca thnh ng thy tinh.+ V cht kh cha trong ng l in mi, nn nu hiu in th gia hai cc ca t in cha t ti hiu in th nh thng v khng c tia phng x bay vo trong t in, th khng c dng in chy trong mch t in.+ Khi cc ht phng x bay vo khng gian gia hai in cc ca ng m, chng s ion ha cht kh lm xut hin cc electron v cc ion. Di tc dng ca in trng gia hai cc cc electron v cc ion chuyn ng v cc in cc to ra dng xung in ngn.+ Cc xung in ny c khch i, a vo my m xung in t hiu s OCA-04M. Cc xung in ny ng thi c a vo mt b tc ng m thanh trong my m xung in t to ting ku ''chp chp''. Mi ting ''chp'' bo hiu s xut hin ca mt xung in khi c ht phng x bay lt vo trong ng m.

Cu 12. Nu r quy lut thay i tc m ph thuc vo dy ca tm kim loi t chn gia ngun phng x v ng m Geiger-Muller. Trnh by phng php xc nh h s hp th tia ca tm kim loi?1. Quy lut thay i tc mph thuc vo dy ca tm kim loi t chn gia ngun phng x v ng m Geiger-Muller :+ Khi cho cc tia phng x truyn qua mt tm kim loi, chng s b tm kim loi hp th. Mc hp th cc tia phng x ph thuc vo bn cht v dy ca tm kim loi. Tc m n gim nhanh theo quy lut hm m khi tng dy x ca tm kim loi: n = no.e- xTrong : no: l tc m khi khng c tm kim loi chn gia ngun phng x v ng m e : l c s ca lga t nhin : l h s hp thu cc tiaphng x ca tm kim loi Nu hai tm kim loi c cng bn cht nhng dy khc nhau x1 v x2 t chn gia ngun phng x v ng m, th h s hp thcc tia phng x ca 2 tm kim loi ny tnh bng: Dng my m Geiger-Muller hin s OCA - 04M o phng ca my m. 2. Xc nh h s hp th tia tia phng x ca tm kim loi.+t cng tc gt chn thang thi gian o ca my m xung in t OCA-04M v tr 1Min. Lp t li ngun phng x RS v ng m GM, trong ngun phng x RS c t nga ln pha trn v ng m GM hng thng ng xung pha di sao cho cc ca s ca chng nm i din st nhau. + Ni lng vt hm v dch chuyn ng m GM t chn va st mt bn kim loi c dy d nm gia ng m GM v ngun phng x RS. My m t ng o s xung din N1 trong thi gian 60s. c v ghi gi tr N1, t tnh c tc m n1 ng vi dy ca mt tm ng kim loi. Thc hin php o ny 3 ln tnh tc m trung bnh v sai s trung bnh.+ Dch chuyn tip ng GM t chn va st 4 bn ng kim loi c cng dy d nm gia ng m GM va ngun phng x RS. My m t ng o xung in N2 trong thi gian t=60s. c v ghi gi tr N2, t tnh c tc m n2 ng vi dy x2=4x ca 4 bn ng kim loi.Thc hin php o ny 3 ln tnh tc m trung bnh v sai s trung bnh.H s hp th phng x 1 ca tm ng kim loi bng:

+ Thay cc bn ng kim loi bng cc bn nhm kim loi c cng dy x'. Thc hin cc php o tng t nh trn o s xung in N'1 v N'2. T suy ra tc m trung bnh v xc nh h s hp th phng x 2 ca cc tm nhm kim loi:

Cu 13. Cu to Nguyn l hot ng my quang ph?My quang ph gm cc thnh phn chnh:Ngun sng.B phn tn sc.B phn ghi o quang in.Ngun sng l cc n chiu sng c di sng tng i rng ty theo bc sng ca php o m ngi ta c th s dng cc loi ngun khc. Th d: ngi ta thng dng n tungstan cho vng kh bin, n thy ngn cho vng t ngoiB phn tn sc l cc lng knh hoc cch t dng to ra cc bc sng khc nhau. i vi my quang sc b phn ny thng l knh lc.B phn ghi o quang in l cc thit b c kh nng bin nh sng thnh in v khuch i ln (nu cn) v c dn qua ng h (bng kim hoc hin s) t xc nh c nng thng qua cc bin i v in da trn c s xc nh hp th nh sng.

1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) Cu 14. nh lut hp th nh sng (Bougeur Lamber Beer)?i vi mt chm tia song song, n sc khi i qua mt dung dch c chiu dy l, nng C th cng ca n b gim theo hm s m ca l, C ng vi biu thc sau:I = I010-lc I0: Cng tia ti. I: Cng tia l. C: Nng dung dch. l: B dy dung dch m nh sng truyn qua. : H s hp th phn t, n ph thuc vo bc sng nh sng ti, bn cht v nhit mi trng.Biu thc trn ch chnh xc khi nng khng qu cao.

Cu 15. Mt quang, truyn qua T?i lng D = .l.C c gi l mt quang, n cho thy mc hp th nh sng ca dung dch. R rng D cng ln, dung dch hp th nh sng cng nhiu.Ngi ta gi t s cng gia tia l v tia ti l truyn qua T, ta c: Nh vy i lng T cho bit mc truyn qua ca tia sng i vi mt dung dch cho trc no (tc l cho bit s phn trm cng truyn qua).T biu thc ca nh lut Bougeur Lambert Beer ta c th rt ra c lin h ca D v T nh sau:D = lg

Cu 16. Cc phng php xc nh nng bng my quang ph?Nu chi tit 1 phng php (bt k)?C 3 phng php:Phng php o trc tip.Phng php pha chun so snh.Phng php lp ng chun.Phng php o trc tip:T biu thc D = .l.C ta thy nu xc nh c l ta c th tnh c

B dy l c th xc nh mt cch gn ng bng cch o b dy cuvet hiu chnh vi b dy thy tinh.H s hp th phn t c c bng cch tra bng (km theo cc chun v bc sng, nhit ,) i vi tng cht. Phng php ny t c s dng v nhiu sai s trong php o.