PHNG GD & T HUYN GIA LM

PHNG GD & T HUYN GIA LM

TRNG THCS NH XUYN

H v tn : ......................................

Lp : 7.......KIM TRA HC K II

MN VT L 7 Nm hc 2014 2015Thi gian lm bi : 45 (pht)

S 1I. Trc nghim (3 im) Khoanh trn ch ci ng trc cu tr li ng.

Cu 1 . Trong cc vt liu di y, vt cch in l

A. Mt on dy thp C. Mt on dy nha

B. Mt on dy nhm D. Mt on rut bt ch

Cu 2 V sao dng in c tc dng nhit ?

A.V dng in c kh nng lm sng bng n bt th in.

B.V dng in c kh nng lm t lit thn kinh .C.V dng in c kh nng lm nng dy dn in.

D.V dng in c kh nng lm quay kim nam chm.

Cu 3Vn k trong s mch in no di y c mc ng?

A

BCD

Cu 4 Mt vt mang in tch m. l do nguyn nhn no di y

A. Vt mt bt in tch dngC. Vt mt bt lectron

B. Vt nhn thm lectronD. Vt nhn thm in tch dng

Cu 5 n v o hiu in th l g?

A. Vn (V).B. Hc (Hz).C. xiben (dB).D. Ampe (A).

Cu 6 Trn bng n in c ghi 110V. Bng n hot ng bnh thng khi mc vo hiu in th no?A. Nh hn 220VB. Ln hn 110VC. 110VD. Mc vo hiu in th no cng c

II. T lun (7 im).

Cu 1 : (2im) Nu s lc v cu to nguyn t.

Cu 2: (1 im) in t vo ch trng:

a) S ch ca vn k l................... b) S ch ca vn k l.............

Cu 3: (3im) Cho mch in gm 1 ngun in (2pin); 2 bng n 1, 2 mc ni tip; 1ampe k o cng dng in chy trong mch; 1 kha K ; dy dn.a. Hy v s mch in v v thm cht dng (+), cht (-) ca ampe k, chiu dng in chy trong mch khi cng tc ng.

b. Da vo s mch in trn; bit s ch ampe k l 1A, hiu in th gia hai u n 1 l U1= 1,8V v hiu in th gia hai u ngun in U= 3V.Tnh: Cng dng in qua mi nv hiu in th gia hai u n 2 (U2) ? Cu 4: (1im) Cho mch in nh hnh v. in c, khng vo trngCng tc ng

n sng

Chung reo

K1

K2

K3

PHNG GD & T HUYN GIA LM

TRNG THCS NH XUYN

H v tn : ......................................

Lp : 7.......KIM TRA HC K II

MN VT L 7 Nm hc 2014 2015Thi gian lm bi : 45 (pht)

S 2I. Trc nghim (3 im) Khoanh trn ch ci ng trc cu tr li ng.Cu 1 . Trong cc vt liu di y, vt dn in l

A. Mt on dy thng C. Mt on dy nha

B. Mt on dy len. D. Mt on dy ch.

Cu 2 V sao dng in c tc dng t ?

A . V dng in c lm sng bng n bt th in.

B . V dng in c kh nng lm t lit thn kinh .

C . V dng in c kh nng lm nng dy dn in.

D . V dng in c kh nng lm quay kim nam chm.

Cu 3Ampe k trong s mch in no di y c mc ng?

A

BCD

Cu 4 Mt vt mang in tch dng. l do nguyn nhn no di y

A. Vt mt bt in tch dngC. Vt mt bt lectron

B. Vt nhn thm lectronD. Vt nhn thm in tch dng

Cu 5 n v o cng dng in l g?

A. Vn (V).B. Hc (Hz).C. xiben (dB).D. Ampe (A).

Cu 6 Trn mt qut in c ghi 220V. Qut in hot ng bnh thng khi mc vo hiu in th no?A. 220VB. Nh hn 220VC. Ln hn 220VD. Mc vo hiu in th no cng c

II. T lun (7 im).

Cu 1 : (2 im) K tn cc tc dng ca dng in. Ly v d minh ha vi mi tc dng.

Cu 2: (1 im) in t vo ch trng:a) S ch ca ampe k l................... b) S ch ca ampe k l.............

Cu 3: (3 im) Cho mch in gm 1 ngun in (2pin); 2 bng n 1, 2 mc ni tip; 1ampe k o cng dng in chy trong mch; 1 kha K ; dy dn.a. Hy v s mch in v v thm cht dng (+), cht (-) ca ampe k, chiu dng in chy trong mch khi cng tc ng.

b. Da vo s mch in trn; bit s ch ampe k l 1,5A, hiu in th gia hai u n 1 l U1= 2,4V v hiu in th gia hai u c 2 n l U= 4,9V. Tnh: Cng dng in qua mi nv hiu in th gia hai u n 2 (U2). Cu 4 : (1im) Xem mch in c v theo s mch in sau v cho bit n no sng bng cch in tn n sng (1, 2, 3)vo bng sau:

Cng tc ng

n sng

K1 v K2

K2 v K3

K1 v K3

PHNG GD & T HUYN GIA LM

TRNG THCS NH XUYNP N THI HC K II

MN VT L 7

Nm hc 2014 2015

I. Trc nghim (3 im)

Mi ng 0,5 im

s 1

Cu

1

2

3

4

5

6

p n

CCBBA

C

s 2

Cu

1

2

3

4

5

6

p n

D

D

C

C

D

A

II. T lun (7 im)

s 1 s 2im

Cu 1:

Tm nguyn t c 1 ht nhn mang in tch dng.

Xung quanh ht nhn c cc electron mang in tch m chuyn ng rt nhanh to thnh lp v nguyn t.

Tng in tch m ca cc eltrn c tr s tuyt i bng in tch dng ca ht nhn. Do bnh thng nguyn t trung ha v in.Eltrn c th dch chuyn t nguyn t ny sang nguyn t khc, t vt ny sang vt khc.Cu 1:

Dng in c 5 tc dung: tc dng nhit, tc dng pht sng, tc dng t, tc dng ha hc, tc dng sinh l. Ly v d2

Cu 2: a) S ch vn k l 3,0Vb) S ch ca vn k l 8,2VCu 2:

a) S ch ampe k l 7,0Vb) S ch ca ampe k l 0,8V0,5

0,5

Cu 3:

a, V ng s mch in

Ghi ng cht + - ca ampe k

Xc nh ung chiu dng in

b, Tnh

I = I1 = I2 = 1A

U = U1 + U2

( U1 = U - U2 ( U1 = 3 1,8 = 1,2V Cu 3: a, V ng s mch in

Ghi ng cht + - ca ampe k

Xc nh ng chiu dng in

b, Tnh

I = I1 = I2 = 1,5A

U = U1 + U2

( U2 = U - U1 ( U2 = 4,9 2,4 = 2,5 V1

1

1

Cu 4:

Cng tc ng

n sng

Chung reo

K1

khngcK2

ccK3

ckhng

Cu 4:

Cng tc ng

n sng

K1 v K2

1 v 2

K2 v K3

Khng

K3 v K1

2 v 3

1

1

K3

K2

K1

2

3

V

V

b

a

+

-

A

K

-

+

-

+

A

K

-

+

K

-

+

+

-

A

-

+

A

K

-

+

Chungg

K2

K1

K3

V

V

+

-

V

K

-

+

-

+

V

K

-

+

K

-

+

+

-

V

-

+

V

K

-

+