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1. 18
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2. F ˆ F www.schoolDD.com 1
18
F F F ˂ F F F F
18.1 F ˂ F F
F F
1. F ˂ (∆E) F F (∆B)
2. F F (∆B) F ˂ (∆E)
3. ˂ F
4. F ˂ F F ˂ F F
ˈ F ˂
- F ˂ ˈ F
- F ˂ F F F F
- F ˂ F (3 x 108
m/s)
18.2 F
cറ
Bሬሬറ
Eሬሬറ
cറ
Bሬሬറ
Eሬሬറ
F ˂
F ˂F ˂ F Eሬሬറ Bሬሬറ
cറ
Bሬሬറ
Eሬሬറ
Z
Y
X
R
B G D
F ˂ F
S
A

3. F ˆ F www.schoolDD.com 2
F F F F F F
F A F F B F ʽ ʽ F ˈ
F ˂ ʽ ʽ F F
F F ˂
B B F A F F G
F F F ˂ ˂ F F G spark ˈ
F ˂ F F ˂ F F G
F ˂ F F D F F D F F ˂
ˈ spark F F D
F G
18.3 F F ˂
F F ˂ F F ˂
F F F F ˂
F F F
- ˂ Eሬሬറ F Bሬሬറ ˈ ˆ F F F
18.3 F ˂
F ˂ F ˂ F F ˈ F F
F F F F F F
F 3.0 x 108
m/s F F
F
F ˂
v
vሬറ
Bሬሬറ
Eሬሬറ
AC
i
F
(Hz)
F
0 10 102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023

4. F ˆ F www.schoolDD.com 3
18.3.1
ˈ F ˂ F F 106
109
F F F
F ˈ F (modulate) F 2
AM ( Amplitude Modulation)
F AM F F (
F ) F F
F
- F AM F F
- AM F 530 - 1600 F F F F
F F
- ˂ ˂ F F ˂ F AM
FM ( Frequency Modulation)
F FM ˈ F F
- F FM F
- FM F 88 - 108 F
F
F

5. F ˆ F www.schoolDD.com 4
F AM F 2
˂ F FM F F F FM F
ʾ F F F F F FM F F F ˈ
18.3.2 F
F ˈ F ˂ 108
F F F FM F
F ʾ F F F F F F
F ˈ F 80 F
F F F F F
F F F
F F
˂
ʾ F
F F ˈ F F

6. F ˆ F www.schoolDD.com 5
18.3.3
ˈ F ˂ F F 109
1011
F
F F F F F F ˈ F F
F F F ˈ F
18.3.4
ˈ F ˂ F F 1011
1014
F F F
F F F F
F F F F F F F ˈ
F F F ˈ F
18.3.5
ˈ F ˂ 4 x 1014
8 x 1014
F
400 700 F F F F F
F F ˂ F F F F
F F F F F F F F F
F ˈ F F F F F ˆ
F F ˈ F F F F F F F
18.3.6 F( LASER)
F ˈ F ˂ F F F F
F F F F F
1. F F F F F , DVD
2. F F F F
3. F (holography)
4.
5. F F
6. F
7.
8.
9.
10. F ʽ

7. F ˆ F www.schoolDD.com 6
18.6.7 ( F )
ˈ F ˂ F F F 1015
1018
F F F
F F F ʾ F
F F F
F F F F F F F
F ˈ F
18.6.8 F
ˈ F ˂ F F 1017
1021
F F F
F F F F F F
F ˄ F F F F
F F F F
18.6.9
ˈ F ˂ F F ˈ F F
F F
18.7 F ˂
F F ˂ F F F ˂
F ˂
F ˂ ˈ F F F F ˂
˂ F ˈ F
E
E
Bሬሬറ
Eሬሬറ
Z
Y
X
F ˂ F ˂ Eሬሬറ

8. F ˆ F www.schoolDD.com 7
18.7.1
F ˈ F ˂ F F ˂
˂ F
F ˂ F F .
F F F F F F ˈ F
F F F ˈ F (Polarization)
1. F F F
. F F F F F F 1 F F F
˂ F F ˂ F
F ˈ F
2. F
F F F F F F ˈ F
ˈ F F
Y
Eሬሬറ
. ˂ F
Eሬሬറ
Eሬሬറ
. ˂ F F Y
Z F F
Z
F F
Eሬሬറ
Eሬሬറ
Eሬሬറ
Eሬሬറ
. F F F F F F F . F F F F F F F
F

9. F ˆ F www.schoolDD.com 8
F F F F F ˂
˂ F F F ˂ F
F F F θB F F 90°
F F F F ˈ F ˂ F F
F (polarizing angle) F
F F ˈ n ˈ 1
F n1 sin θ1 = n2 sin θ2 ( )
θ1 = θB , θ2 = 90 α = 90 θB , α = θB ( = F )
F F 1 sinθB = n sin (90 θB)
sinθB = n cosθB
tanθB = n
‫׵‬ θB = tan-1
n
F F F θB = tan-1
n F ˈ F
F 1
F F 100.0 F
F ˂ F
F ˂ F 3x 10 8
m/s
v = fλ
λ =
୴
୤
=
ଷ୶ଵ଴ఴ
ଵ଴଴୶ଵ଴ల
‫׵‬ λ = 3.0 m Ans
αθB
θ2
90°
F
F ˈ F

10. F ˆ F www.schoolDD.com 9
F 2
F F F 48° F F ˈ
F ˈ F
F F n1 sin θ1 = n2 sin θ2
1 sin 48 = n2 sin 42
ୱ୧୬ ସ଼
ୱ୧୬ ସଶ
= n2
n2 = ୱ୧୬ ସ଼
ୡ୭ୱ ସ଼
= tan 48 = 1.11 Ans
F F F F
F 3
F F F 37°
n1 sin θ1 = n2 sin θ2
n1 sin θc = n2 sin 90
1 sin37 = n2 (1.0)
n2 = sin37 =
ଷ
ହ
= 0.6
n1 = 1
42° n2 = ?
48°48°
n1 = 1
n2 = ?
θc = 48°

11. F ˆ F www.schoolDD.com 10
F
n1 sin θ1 = n2 sin θ2
n1 sin θB = n2 sin (90 - θB)
1 sin θB = n2 cos θB
n2 = tan θB
0.6 = tan θB
‫׵‬ θB = tan-1
0.6 = 30.96° Ans
“
1
....
”
n1 = 1
n2 = 0.6
θB θB
90- θB
θB = ?