Vdy chgn dap an D.
Trang 1Cdu 25:
H ie
u di en
the giff
a ano'
t v
a cato't cu
a mo
t o'n
g Rornghe
n l
a
U = 2 5k
V Co
i v an toe ba
n da
u cua chu
m electro
n (electron ) pha
t r
a tt
f
catot bk ng khong Bie
t han
g s
o Plan
g h = 6,625.10~^^J.s
, die
n tich
nguyen
to ban
g 1,6.10'^^C T
an
so
Idm n ha
t cu
a tia Rornghen
do
ong
nay c6 th
e pha
t r
a l a:
A 6,038.10^^Hz '
B 60,380.10^^Hz
C 6,038.10^^Hz D
60,380.10'^Hz
Giai
PT J
Ta c6: e
U = h f=
> f = —
= 6,038.10"
Vdy chgn dap an
A
Cdu 26:
M
ot kh un
g d ay d an
h in
h chO
r n ha
t c
6 10
0 vong
, die
n tich
moi
vong
600 cm^
, qua
y de
u quanh true do
i xufn g
cua khun
g vdf
i va
n to
e go
e
120 vong/phu
t tr on
g mo
t tC
f truf&n
g de
u eo ca
m ufn
g ttf ban
g 0,2T
Tru
e
quay vuon
g go
e vd
i ca
c dUorn
g cam ufng
tCr Cho
n go
e thor
i gia
n l
a lu
e
vectof pha
p tuye
n cu
a m
at phSn
g khun
g da
y ngUtf
c hifdfng vdf
i vecto
r ca
m
ufng tii.
Bieu thufc sua
t die
n don
g cam
ufng tron
g khun
g la :
A e = 4,8;isi
n 4 0;
rt
2
C e = 4 87 1 sin 40 7r
t 2 (V ) B e
= 487tsin(4;r
t + n )(
V)
(V ) D e
= 4,87isin(407r
t +
7
i
)(V
)
Giai
Theo d
e ba
i, ta c6:
+ D ie
n t ic
h von
g day : S = 600cm
^ = 6.10"^m^
+ S
o von
g day : N = 10
0 vong
•f Ca
m ufn
g tCr : B = 0,2T
+ Td
c d
o qua
y cu
a roto : 12
0 vong/phu
t =
2 vong/giay
Vao thcf
i die
m t =
0, go
e giff
a pha
p tuye
n cu
a khun
g da
y v
a ca
m
ufng tf
f l
a a
= 71
Ta
C
O tC
f t ho ng qua mo
t von
g da
y l a:
cp, = BScos(a
+ 7r ) = BScos(27rn
t +
7r)
Vi kh un
g da
y c
6 N vong
giong nhau nen t ro ng khung
c6 sua
t die
n
dong: e = -N
^ = NBS27msin(27mt +
7r)
Thay
so ta c6: e = 4,87isin(407r
t +
7 i
)(V )
Vdy chgn dap an
D
12
Giai Ch
i ti^
t d
S th
i TS
DH,
CD
M6n
V^t I
f