- Nham: dqc dung lam cac chi tiet tiep xuc cJ can lay di$n cua cac ph cJng ti$n v(m tai bang di$n.
cAu HOI ONT,;P
1) Tr1nh bay khai ni$m ve v$t li$u dan di$n? Neu tf nh chat cua v$t li$u dan dien?
2) Tr1nh bay di$n tra va di$n tra suat? Cho biet nhi$t d9 anh h- ang nh- the nao den dien tra cua vat lieu? . . .
3) Cac tac nhan cua moi tr- c:1ng anh h- ang nh- the nao den v$t li$u dan di$n? 4) The nao la hi$u di$n the tiep xuc va sCtc nhi$t d9ng?
5) Neu cac tf nh chat chung cua kim lo9i va hgp kim?
6) Neu nhCtng h- hong th- c:1ng g$p cua v$t li$u dan di$n, nguyen nhan va bi$n phap khac phuc?
' .
7) Neu tfnh chat, d$c diem va cong dyng cua dong va hgp kim dong, nhorn va hgp kim nhom, ch1 va hgp kim chi?
8) Tr1nh bay cac yeu to anh h- ang den di$n tra tiep xuc va d9 ben tiep diem ? Cho biet cac v$t li$u d-gc dung lam tiep diem?
9) Neu nhCtng hgp kim c6 di$n tra cao va ch!U nhi$t? Neu m9t so hgp kim dien h1nh?
10) The nao la I- Bng kim, nhi$t I- Bng kim hay tr1nh bay va cho m9t val vf dy minh hoa.
❖ Cau hoi tr c nghi~m h/a ch9n.
09c ky cac cau hoi, ch9n y tra lc:1i dung nhat va to den vao o thfch hgp a c9t ben:
TT Nqi dung cau hoi a b C d 3.1 V$t li$u c6 thanh phan gom (60% Cu+ 4O%Ni) c6 ten g9i □ □ □ □
la:
a. Constantan. b. Mai so.
c. Ferro - Niken. d. Niken - Crome
3.2 M9t loc:1i v$t li$u rat thong dyng de lam cac tiep diem cat □ □ □ □ c6 yeu cau chfnh xac, n6 c6 d9 cung cao, nhi$t d9 n6ng
chay va di$n dan suat cao, c6 sue ben doi vc:5i SI/ an mon lo9i v$t li$u d6 la:
a. Paladi. b. Platin. c. Molipden. d. Rodi.
3.3 0oi vc:5i tiep xuc co djnh lam vi$c trong moi tr- e5ng am - c:5t □ □ □ □ ng- e5i ta khong dung dong va nhom tiep xuc vc:5i nhau la
do:
a. Chung c6 di$n tr6 suat khac nhau. b. Chung c6 tr9ng I- gng khac nhau.
c. Chung c6 di$n the h6a h9c h6a h9c khac nhau. d. Chung c6 tfnh chat v$t ly khac nhau.
3.4 Hc;Jp kim di$n tr6 chu yeu lam di$n tr6 toa nhi$t trong □ □ □ □ ban ui, bep di$n, mo han va c6 nhi$t d9 v$n hanh cao
9OO°C va c6 di$n tr6 suat: 1,02 Qmm2/m (6 2O°C) hc;Jp kim d6 la:
a. Niken - Crome: ( 80% Ni+ 2O%Cr). b. Sat - Niken - Crome.
c. Ferro - Niken. d. Constantan.
3.5 Day dan I- Bng kim thep - dong d- <;Jc dung nhieu de lam: □ □ □ □
a. 0- ong day thong tin dung dong di$n c6 tan s6 cao. b. 0- Ong day trung the.
c. 0- Ong day ha. the. d. 0- ong day cao the.
3.6 Hgp kim c6 thanh phan (74% Fe+ 25% Ni+ 1%Cr) c6 ten D D D D
g9i la:
a. Constantan.
b. Sat - Niken - Crome. c. Ferro - Niken.
d. Niken - Crome.
3.7 Trong nhi$t I- Bng kim khi can llfa ch9n V?t li$u c6 h$ s6 D D D D
gian d theo chieu dai ft th1 ng- oi ta dung: a. Hgp kim dong - kem.
b. Hgp kim dong thanh nhom. c. Thep hgp kim cram - Niken. d. Hgp kim Niken (H36: lnva).
3.8 Hgp kim c6 di$n tro cao, thanh phan:(60% Cu+ 25% Zn + D D D D
15%Ni), c6 ten g9i la: a. Constantan. b. Mai so.
c. Ferro - Niken. d. Niken - Crome
3.9 Ltfc an tiep diem la yeu t6 rat quan tr9ng anh hong t&i D D D D
di$n tro tiep xuc cua tiep diem, khi llfc an tang th1 di$n tro tiep xuc se:
a. Tang.
b. Khong thay d6i. c. Giam.
d. Tang rat nhieu.
3.10 V&i khoang nhi$t de) nao cua tiep diem th1 n6 se lam D D D D
giam di$n trb tiep xuc: a. V&i nhi$t d9 < 250°C. b. VC1i nhiet do < 1 oo0c.
c. VC1i nhiet do > 500°C.
d. V&i nhi$t d9 giCl'a (250 7 400)°C.
3.11 Bong thau la hgp kim cua dong v&i: □ □ □ □
a. Niken. b. Thiec.
C. Kem .. d. Ch1
3.12 Bura la hgp kim cua nh6m v&i dong, magie va mangan n6 □ □ □ □ thu6c nh6m:
a. Hgp kirn nhom due. b. hgp kim nhom bien d,~mg. c. Silumin.
d. Khong xac d!nh.
3.13 Nham c6 09 tinh khiet cao nhat d-gc ky hi$u: □ □ □ □
a. AB1. b.AB2. c. A- 00. d. A-1.
3.14 Bong thanh la hgp kim cua dong v&i cac nguyen to: □ □ □ □ a. Ykim.
b. Kim loai den.
c. La dong d-gc che t<?o thanh thanh. d. V&i cac nguyen to kim lo<?i khac tru kem.
3.15 Tfnh gia h6a cua kim lo<?i la: □ □ □ □
a. Sy' thay doi theo the1i gian cua cac tfnh chat kim loai.
b. Thay doi ve d9 cCfng do nhi$t luy$n.
c. Thay doi ve thanh phan h6a h9c khi san xuat. d. Thay doi do sy' an mon h6a h9c cua m6i tr- e1ng.
3.16 CJ nhi$t d9 kh6ng tuy$t doi (0°K), di$n tra suat cua kim □ □ □ □
loai tinh khiet se: a. Giam d9t ng9t. b. Tang d9t ng9t. c. Tang tu'tu.
d. Khong anh h- 6ng.
3.17 8i$n dan suat c6 cong thCfc tfnh nh- sau:
1 a. G=-. R b. _!_ = n-1 • Q d . R=p-l s □ □ □ □
3.18 Kim loai khong bi tac dt,mg cua axit clohydrc, axit □ □ □ □ sunfuaric, axit sunfuaro, fluorhydric, phosphoric hoac
amoniac, sut, borax va clo, nh- ng 19i haa tan d~ dang trong axft nitorfc d6 la:
a. Ch1 b. Nham. c. Dong. d. Thiec.
3.19 Khi can llfa ch9n v~t li$u dan di$n ta can cu vao: a. 89 dan di$n, d9 ben chong an man.
b. 89 ben co, d9 ben chong an man.
c. 89 dan di$n, d9 ben co, d9 ben chong an man. d. Ch9n v~t li$u dong nguyen chat.
3.20 Sue ben cua tiep di§m bi anh h- 6ng b6i:
a. Ban chat be m~t tiep di§m, llfc an tiep di§m. b. Nhi$t d9, ban chat be m~t, ILjc an tiep di§m. c. Tr9ng thai ve be m~t khi tiep xuc.
d. Ban chat, tr9ng thai be m~t, nhi$t d9 va llfc an tiep di§m.
Khoa nietl - Trb6ng TCN KTCN Hung Voong
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3.21 Tf nh t1i$n trb cua m9t day dan bang dong c6 tiet di$n □ □ □ □ 0,2cm2, di$n trb suat 1,75x10-8, chieu dai 100m.
a. 8,75x 10-2Q. b. 8,75x 10-4n . c. 8,75x 10-SQ. d. 8,75x 10-6n
3.22 M9t day dan bang dong c6 chieu dal 1 km th1 c6 di$n trc:J □ □ □ □ la 8,7Q; neu ta d- a day dan d6 ch$p doi 19-i de d- qc day
dan !cm hon va c6 chieu dai la 500m. V$y di$n trc:J cua day dan sau khi ch$p 19-i c6 gia tri la:
a. s,7n. b. 17,4n.