Part 2

Question 1

electrically short when its physical length is
short compared to a quarter- wavelength of the energy it is to carry.

Answer 1

Transmission line

Question 2

electrically long when its physical length is long compared to a
quarter-wavelength of the energy it is to carry

Answer 2

Transmission Line

Question 3

When power is applied to a very short transmission line, practically all of it reaches the ____________.

Answer 3

load at the output end of the line

Question 4

very short transmission line is usually considered to have practically _____________, except for a small amount of resistance

Answer 4

no electrical properties of its own

Question 5

The electrical characteristics of a two-wire transmission line depend primarily on the __________________

Answer 5

construction of the line

Question 6

The two-wire line acts like a

Answer 6

long capacitor

Question 7

Each type of two-wire transmission line also has a ___________, wherein it represents the value of the current flow that may be expected through the insulation

Answer 7

conductance value

Question 8

Ideally, a transmission line would also have its constants of inductance, capacitance, and
resistance lumped together.

Answer 8

lumped constants

Question 9

simplification, representing the distributed nature of the
transmission line parameters as lumped elements per unit length.

Answer 9

The equivalent circuit of a two wire transmission line

Question 10

The analysis of transmission lines often involves ___________ derived
from these differential equations to determine voltage and current behavior along
the line.

Answer 10

solving the wave equations

Question 11

Transmission line constants are distributed. A line infinitely long can be represented by

Answer 11

an infinite number of inductors and capacitors

Question 12

Transmission line constants called ____________ spread along the entire
length of the transmission line and cannot be distinguished separately.

Answer 12

distributed constants

Question 13

in distributed constants, the amount of inductance, capacitance, and resistance depends on the __________ between the wires

Answer 13

length of the line,
the size of the conducting wires,
the spacing between the wires,
and the dielectric
(air or insulating medium)

Question 14

When current flows through a wire, it generates magnetic lines of force around the wire.

Answer 14

Inductance of a Transmission Line

Question 15

In inductance of a transmission line, as the current amplitude changes, the magnetic field ______________

Answer 15

expands and collapses

Question 16

The collapsing magnetic field __________ into the wire, maintaining the current flow.

Answer 16

induces energy back

Question 17

unit of inductance per unit length

Answer 17

microhenrys

Question 18

Two parallel wires in a transmission line act as plates of a capacitor.

Answer 18

Capacitance of a Transmission Line

Question 19

In a capacitance of a transmission line, the air or insulating material between the wires serves as the ______. This setup creates an electric field similar to that of a capacitor.

Answer 19

dielectric

Question 20

unit of capacitance per unit length

Answer 20

picofarads

Question 21

existing continuously from one end of the line to the other.

Answer 21

Resistance of a Transmission Line

Question 22

unit of resistance per unit length

Answer 22

ohms

Question 23

Since any dielectric, even air, is not a perfect insulator, a small current known as ____________ flows between the two wires

Answer 23

Leakage Current

Question 24

In effect of a leakage current, the insulator __________, permitting current to pass between the two wires.

Answer 24

acts as a resistor

Question 25

This leakage path as resistors in parallel connected between the two lines. This property is called ________ and is the opposite of resistance.

Answer 25

CONDUCTANCE (G)

Question 26

Conductance in transmission lines is expressed as the __________ and is usually given in _______ per unit length.

Answer 26

reciprocal of resistance, micromhos

Question 27

The most efficient transfer of electrical energy takes place when __________

Answer 27

the source impedance is matched to the load impedance

Question 28

If the characteristic impedance of the transmission line and the load impedance are equal, energy from the transmitter _________ caused by reflection

Answer 28

will travel down the transmission line to the antenna with no power loss

Question 29

the input impedance of a transmission line either infinitely long or terminated in a pure resistance exactly equal to its characteristic impedance.

Answer 29

Character Impedance

Question 30

another name for characteristic impedance.

Answer 30

Surge Impedance

Question 31

impedance Zo formula

Answer 31

Zo = sqrt of (L/C)

Question 32

Characteristic Impedance of a Two wire Line formula

Answer 32

Zo = 276 / sqrt of 𝜖 * log10(2D/d)

Question 33

Characteristic Impedance of a concentric or coaxial line

Answer 33

𝑍𝑜 ≈ 138/sqrt of 𝜖 * log10(𝐷/d) where D = inner diameter of the outer conductor d = outer diameter of the inner conductor 𝜖 = dielectric constant of the insulating material relative to air

Question 33

Velocity Factor and Dielectric Constant of Different Materials

Answer 33

memorize from table