1,50 diem Phat bieu qui t~c nam tay phai xac dinh chien dirong sire tir cua 6 g day co dong dien chay qua khong ve hinh.. Hieu dien thS gitra hai diem M, N khong d6i.. Dien tro cua ampe
Trang 1sa GIAo DV C vA DAo T ~o
KHANHHOA
DE KIEM TRA HQC KY I NAM HQC 2013-2014
MOD: V~T LV lop 9
Thai gian : 45 phut (khong ki thai gian phat d€)
Cau 1.(2,00 diem)
Phat bieu va viet h~thtrc cua dinh lu?t Om Neu r5 ky hieu, don v i cua cac dai hrong co trong M
Cau 2 (1,50 diem)
Phat bieu qui t~c nam tay phai xac dinh chien dirong sire tir cua 6 g day co dong dien chay qua (khong ve hinh)
Cau 3 (2,50 diem)
MQt day d~n co chieu dai 10m, tiSt dien tron, lam bang chat co di~n tro suat 0,50.1 -6 O m, va co
di~ntro 25 0 Tin dirong kinh cua day BiSt 7r =3,14
- - - lIS t-
-Cau 4 (4,00 di~m)
Co mot mach dien nhi hinh ve sau :
Trong do RI =20 0., R2= 30 0., R3= 8o .
Hieu dien thS gitra hai diem M, N khong
d6i Dien tro cua ampe kSva day n6i k ong
dang k~
a) Khi K ng~t (mo), ampe kSchi 0,5A Tinh :
a Dien tro tuong duo g cua doan mach MN
a2.Hieu di~n thS giira hai diem M, N
ai Nhiet hrong toa ra tren dean mach MN
trong 30 phut ra don vi Jun va calo
b) Khi dong cong t~c K, tinh :
bi.Di~n tro nrong dirong cua doan mach MN
b2.sechi cua ampe kS
b3.Cong su~t tieu thu tren dien tro R3
+
Trang 2H110NG DAN CHAM MON VAT LY
KiSm tra HQcky 1,nam hoc 2013-2014
Cau 1 :2,00 diSm (SGK trang 8)
- Dinh luat Om:
CUOngdQ dong di~nchay qua day d~n ti l~thuan
voi hieu di~n thS d~tvao hai ddu day
vati l~nghich voi di~n tro cua day.
- He. thirc cua dinh luat : 1= U R
- Trong do , I: cirong dQ dong di~n chay trong day d~n, do bang ampe (A),
R: dien tro cua day d~n , dobang om (.0),
U: la hieu dien the, dobang von (V)
Csu 2 :1,50 di~m (SGK trang 66)
Nam ban tay phai,
r6i d~t sac cho b6n ngon tay huang thee chieu dong dien chay qua cac vong day
thi ngon tay cai choai ra chi chieu cua dirong sirenr trong long 6ng day.
Cau 3: 2,50 diSm
T'u cong t ucA hu : R= p- I
S
I
== > S =
p-R
= 0,5.10-6.!.2.= 0,2.lO-6 m2 = 0,2 mm".
25
rx , » kinh cr dA S d
d= 2~O,2 ~050mm
314, '
==>d = 2~
Cau 4: 4,00 diem
a Khi Kmo : (2,00 diem)
ar Khi Kmo thi doan mach MN g6m R3 n6i tiep Rl n6i tiSp ampe kS.
Dien tro tuong duong cua dean mach MN :RMN = R3 +R,
= 8 + 20 = 28Q
a2 ampe kS chi 0,5A nen I=0,5A
Hieu dien thSgitra hai ddu c u a dean mach MN :UMN = I RMN = 0,5.28 = 14 V
a3 Nhiet lUQ11gt6a ra tren dean rnach MN :Q = U.1 t
=14.0,5.30.60 =12600 J
=0,24 12600 = 3024 calo
( hay Q = RMNet = 28.0,52.30.60 = 12600 J)
b Khi K dong: (2,00 diem)
bl Dien tro tirong duong cua doan mach MN luc nay:
R ' MN- - R3+ -' =-R(.R 2
R( +R2
= 8 + 20.30 =8 + 12=20 0
20+30
(0,50 d) (0,25 d) (0,50 d) (0,25 d) (0,25 d) (0,25 d)
(0,50 d) (0,50 d) (0,50 d)
(0,75 d)
(0,75 d)
(0,50 d)
(0,50 d)
(0,25 d) (0,25 d)
(0,25 d) (0,50 d) (0,50 d) (0,25 d)
(0,50 d)
(0,25 d)
Trang 3S6 chi c u a ampe k€ hie nay la 0,7A
b3 ViR3 nt RI2 nen 1 = 13 = 0,7A
Cong su~ttieu thu tren R3 :f !J J 3= 132 R3 =
= e.R3= 0 , 8 = 3,92 W
(0,25 d)
b Cu on g dQdong dien chay qua dean mach MN : I' = R~
MN
=.!i=07A
(0,50 d)
(0,25 d)
Ghi chu :MQi each giai khac, n€u dung v~ncho diem t6i da