This document discusses various topics relating to electromagnetic waves and radio communication technologies: 1. It describes the properties and characteristics of electromagnetic waves, including wavelength, frequency, and speed. 2. It explains different modulation techniques used in radio such as amplitude modulation (AM) and frequency modulation (FM). AM varies the amplitude of the carrier wave while FM varies the frequency. 3. It provides an overview of the electromagnetic spectrum, showing the range of wavelengths and frequencies used for communications technologies like radio and television broadcasting.

1. SchoolDD.com
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2. 18
F F F F F F F
18.1 F F F
FF
1. F ( E) F F ( B)
2. F F ( B) F ( E)
3. F
4. F F F F F
F
Y
Z
F
X
F F F
- F F
- F F F F F
- F F (3 x 108 m/s)
18.2 F
R
S
A B G D
F F
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3. F F F F F F
F A F F B F F
F F F
F F
B B F A F F G
F F F F F G spark
F F F F F G
F F F D F F D F F
spark F F D
F G
18.3 F F
i
AC v
F F F F
F F F F
F F F
- F F F F
18.3 F
F F F F F F
F F F F F F
F 3.0 x 108 m/s F F
F F
F
(Hz)
0 10 102 103 104 105 106 107 108 109 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023
F
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4. 18.3.1
F F F 106 109 F F F
F F (modulate) F2
AM ( Amplitude Modulation)
F
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
F FM F F
- F FM F
- FM F 88 - 108 F
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5. F
F AM F2
F FM F F F FM F
F F F F F FM F F F
18.3.2 F
F F 108 F F F FM F
F F F F F F F
F F 80 F
F F F F F
F F F
F F
F F F F
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6. 18.3.3
F F F 109 1011 F
F F F F F F F F
F F F F
18.3.4
F F F 1011 1014 F F F
F F F F
F F F F F F F
F F F F
18.3.5
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 F F F F F
F F F F F F F F F
18.3.6 F( LASER)
F 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
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7. 18.6.7 ( F )
F F F F 1015 1018 F F F
F F F F
F F F
F F F F F F F
F F
18.6.8 F
F F F 1017 1021 F F F
F F F F F F
F F F F F
F F FF
18.6.9
F F F F F
F F
18.7 F
F F F F F
F
F F F F F
F F
Y
E
Z
X E
F F
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8. 18.7.1
Y
Z
. F . F F Y
Z F F
F F F F
F
F F F .
F F F FF F F
F F F F (Polarization)
1. F F F
F F
. F FF F F F F . F F F F F F F
F
. F F FF F F1 F F F
F F F
F F
2. F
F F F F F F F
F F
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9. B
90°
2
F
F F
F F F F F
F F F F
F F F B F F 90°
F F F F F F F
F (polarizing angle) F
F F n 1
F n1 sin 1 = n2 sin 2 ( )
1= B , 2 = 90 = 90 B , = B ( = F )
F F 1 sin B = n sin (90 B)
sin B = n cos B
tan B = n
-1
B = tan n
F F F B = tan-1 n F F
F 1
F F 100.0 F
F F
F F 3x 10 8 m/s
v=f
= =
= 3.0 m Ans
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10. F 2
F F F 48° F F
F F
n1 = 1
48° 48°
42° n2 = ?
F F n1 sin 1 = n2 sin 2
1 sin 48 = n2 sin 42
= n2
n2 = = tan 48 = 1.11 Ans
F F F F
F 3
F F F 37°
n1 = 1
c = 48°
n2 = ?
n1 sin 1 = n2 sin 2
n1 sin c = n2 sin 90
1 sin 37 = n2 (1.0)
n2 = sin 37 = = 0.6
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11. F
n1 = 1
B=?
B B
90 - B n2 = 0.6
n1 sin 1 =n2 sin 2
n1 sin B = n2 sin (90 - B)
1 sin B = n2 cos B
n2 = tan B
0.6 = tan B
-1
B = tan 0.6 = 30.96° Ans
“
1
....
”
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