Optical Properties of Radio Wave

Question 1

The different waves propagated along such multiple paths interfere at the reception

Answer 1

multipath
propagation

Question 2

Refraction of electromagnetic waves can be expressed in terms of refractive index of the atmosphere it is passing through.

Answer 2

𝒏 = /𝝐𝒓 (n = square root of 𝝐𝒓)

Question 3

____ defined as the modulation or redistribution of energy within a wavefront when it passes near the edge of an opaque object.

Answer 3

Diffraction

Question 4

__________ occurs when an incident wave strikes a boundary of two media and some or all of the incident power does not enter the second material.

Answer 4

Electromagnetic reflection

Question 5

states that every point on a given spherical wavefront can be considered as a secondary point source of electromagnetic waves from which the other secondary waves are radiated outward.

Answer 5

Huygen’s principle

Question 6

The amount of bending or refraction that occurs at the interface of the two materials of different densities.

Answer 6

depends on the refractive index of the two materials.

Question 7

As the wave front passes the object, the point sources of waves at the edge of the obstacle create additional spherical waves that penetrate and fill in the shadow zone.

Answer 7

knife-edge diffraction

Question 8

In Earth’s atmosphere, ray-wavefront propagation may be altered from free-space behavior by optical effects such as ________.

Answer 8

refraction, reflection, diffraction and
interference.

Question 9

The ratio of the reflected and incident power densities is called ________________.

Answer 9

reflection coefficient (Γ)

Question 10

_________ is actually the changing of direction of an electromagnetic ray as it passes obliquely from one medium into another with different velocities of propagation.

Answer 10

Electromagnetic refraction

Question 11

______ the phenomenon that allows light or radio waves to propagate (peek) around corners.

Answer 11

Diffraction

Question 12

_ is the angle of incidence that results in an angle of refraction of exactly 90˚

Answer 12

Critical angle

Question 13

The fraction of power that penetrates medium 2 is called ______.

Answer 13

absorption coefficient

Question 14

Interference as _____.

Answer 14

colliding

Question 15

the reflected voltage intensities is less than _________.

Answer 15

incident voltage field intensity

Question 16

_ states that a semi-rough surface will reflect as if it were a smooth surface whenever the cosine of angle of incidence is greater than 𝛌/8d, where d is the depth of irregularity.

Answer 16

Rayleigh criterion

Question 17

refraction becomes a form of reflection

Answer 17

total internal reflection

Question 18

the founder of the wave theory of light.

Answer 18

Christian Huygens

Question 19

The relationship between the angles and the indices of refraction is given by a formula known as.

Answer 19

Snell’s law
𝒏𝟏𝒔𝒊𝒏𝜽𝒊 = 𝒏𝟐𝒔𝒊𝒏𝜽𝒓

Question 20

result from the superposition of oscillations or waves of same nature and equal frequency.

Answer 20

Interferences

Question 21

diffraction as _____.

Answer 21

scattering

Question 22

Surface that fall between smooth and irregular is called

Answer 22

semi-rough surfaces

Question 23

Saying all the reflected waves remain in medium 1, the velocity of the reflected and incident waves _______.

Answer 23

equal

Question 24

It is sometimes referred to as the bending of the radio wave path.

Answer 24

Refraction

Question 25

refractive index can be expressed as

Answer 25

𝒏 = 𝒄/𝒗𝒑

Question 26

The portion of the total incident power that is not reflected is called _______.

Answer 26

power transmission coefficient
(T)

Question 27

refraction can be _______.

Answer 27

bending

Question 28

When an incident wavefront strikes an irregular surface, it is randomly scattered in many directions. Such condition is called ____.

Answer 28

diffused reflection

Question 29

critical angle can be expressed as ___.

Answer 29

𝜽𝒄 = 𝐬𝐢𝐧^−𝟏 𝒏𝟐/𝒏𝟏

Question 30

Whereas reflection from a perfectly smooth surface is called

Answer 30

specular (mirrorlike) reflection

Question 31

reflection can be _______.

Answer 31

bouncing