quiz 1

Question 1

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

Answer 1

output end of the line

Question 2

A transmission line is considered to be ____ when its physical length
is short compared to a quarter- wavelength of the energy it is to carry

Answer 2

electrically short

Question 3

A transmission line is considered to be ____ when its physical length is long compared
to a quarter-wavelength of the energy it is to carry.

Answer 3

electrically long

Question 4

This very short transmission line is usually
considered to have practically no electrical properties of its own, except for a
small amount of

Answer 4

resistance

Question 5

mostly used transmission line

Answer 5

electrically long

Question 6

the voltage necessary to drive a current through a long line is
considerably greater than the amount that can be accounted for by the _____ of the load in series with the resistance of the line

Answer 6

impedance

Question 7

depend primarily on the
construction of the line

Answer 7

two-wire transmission line

Question 8

acts like a long capacitor

Answer 8

two-wire line

Question 9

have a magnetic field about them when electrical energy is being passed through them, they also exhibit the properties of inductance

Answer 9

long conductors

Question 10

The effects of the inductive and capacitive reactances of the line depend
on the _______ applied

Answer 10

frequency

Question 11

electrons manage to move from one conductor to the other
through the

Answer 11

dielectric

Question 12

Each type of two-wire transmission line also has a

Answer 12

conductance value

Question 13

represents the value of the current flow that may be expected through the insulation

Answer 13

conductance value

Question 14

has the properties of inductance, capacitance, and resistance
just as the more conventional circuits have

Answer 14

transmission line

Question 15

has the property of inductance

Answer 15

coil of wire

Question 16

can be used to supply the required
capacitance for a circuit

Answer 16

Two metal plates separated by a small space

Question 17

can be used to supply a
certain value of circuit resistance as a lumped sum

Answer 17

fixed resistor

Question 18

The equivalent circuit of a two-wire transmission line, in the context of electrical engineering, is represented by a

Answer 18

series combination of a small inductance (L) and resistance (R) per unit length, in parallel with a small capacitance (C) and
conductance (G) per unit length

Question 19

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

Answer 19

DISTRIBUTED CONSTANTS

Question 20

The amount of inductance, capacitance, and resistance depends on the
length of the line, the size of the conducting wires, the spacing between the
wires, and the dielectric (air or insulating medium) between the wires.

Answer 20

DISTRIBUTED CONSTANTS

Question 21

are set up around the wire when current flows through a wire

Answer 21

magnetic lines of force

Question 22

The energy produced by the magnetic lines of force collapsing back into the wire tends to keep the current flowing in the same
direction. This represents a certain amount of

Answer 22

inductance

Question 23

inductance is expressed in

Answer 23

microhenrys per unit length

Question 24

The capacitance between the wires is usually expressed in

Answer 24

picofarads per unit length

Question 25

act as plates of a capacitor

Answer 25

two parallel wires

Question 26

the air between two parallel wires acts as a

Answer 26

dielectric

Question 27

resistance is usually expressed in

Answer 27

ohms per unit length

Question 28

is shown as existing continuously from one end of the line to the othe

Answer 28

resistance

Question 29

a small current that flows between the two wires

Answer 29

LEAKAGE CURRENT

Question 30

acts as a resistor, permitting current to pass between the two wires

Answer 30

insulator

Question 31

is the opposite of resistance or expressed as the reciprocal of resistance

Answer 31

CONDUCTANCE

Question 32

This leakage path as resistors in parallel connected between the two lines, what is this property?

Answer 32

CONDUCTANCE

Question 33

Conductance is expressed in

Answer 33

micromhos per unit length

Question 34

The most efficient transfer of electrical energy takes place when the source impedance is matched to the

Answer 34

load impedance

Question 35

If the characteristic impedance of the transmission line and the load impedance are equal, energy from the transmitter will travel down the transmission line to the antenna with no power loss caused by

Answer 35

reflection

Question 36

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

Answer 36

Character Impedance

Question 37

another name for characteristic impedance

Answer 37

Surge Impedance

Question 38

Characteristic Impedance of a Two wire line

Answer 38

D = spacing between the wires (center to center) d = diameter of one of the conductors 𝜖 = dielectric constant of the insulating material relative to air

Question 39

Characteristic Impedance of a concentric or coaxial line

Answer 39

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 40

The distributed analysis of uniform transmission lines was started by

Answer 40

William Thomson (Lord Kelvin) in 1855

Question 41

The distributed analysis of uniform transmission lines was completed by

Answer 41

Oliver Heaviside about 1885.

Question 42

refer to the reduction of power or signal strength as electricity or data travels through a transmission line. These losses occur due to various factors such as resistance, dielectric properties, electromagnetic radiation, and external interference.

Answer 42

Transmission losses

Question 43

are critical in power systems, communication networks, and RF/microwave applications, as they impact efficiency, reliability, and performance.

Answer 43

Transmission losses

Question 44

Types of Transmission Losses

Answer 44

 Copper Losses  Dielectric Losses  Radiation and Induction Losses  Evanescent Wave Losses  Four Wave Mixing

Question 45

Also called “Resistive Losses”, is the most common type of loss, these occur due to the resistance of the conductor material, leading to power dissipation in the form of heat.

Answer 45

Copper Losses

Question 46

are proportional to the square of the current (I²R) and are exacerbated by the skin effect, where high-frequency currents concentrate near the conductor's surface, increasing effective resistance.

Answer 46

Copper Losses

Question 47

At high frequencies, the current tends to concentrate near the surface of the conductor (the "skin"). This reduces the effective cross-sectional area for current flow, increasing resistance and leading to power loss.

Answer 47

SKIN EFFECT

Question 48

are used to minimize skin effect losses

Answer 48

coaxial cables with thick outer conductors

Question 49

In _______, the skin effect can be significant, especially at higher frequencies

Answer 49

radio frequency (RF) transmission lines

Question 50

This means that 20 kW of power is wasted as heat due to resistance. To minimize this loss

Answer 50

increasing the transmission voltage (reducing current) or using a lower resistance conductor would help

Question 51

occur when the insulating material between conductors absorbs energy from the alternating electric field, converting it into heat. These losses depend on the material's dielectric constant and frequency.

Answer 51

Dielectric losses

Question 52

In a coaxial cable, the dielectric material between the inner and outer conductors can experience dielectric losses, leading to

Answer 52

signal attenuation

Question 53

in ____, high-frequency signals passing through dielectric substrates suffer from dielectric heating

Answer 53

microwave transmission

Question 54

The magnitude of dielectric loss is determined by the

Answer 54

dielectric's permittivity and dielectric loss tangent

Question 55

At high frequencies, the transmission line can act as an antenna, radiating some of the electromagnetic energy into space. This is particularly significant for open-wire transmission lines

Answer 55

Radiation Losses

Question 56

If the transmission line is located near metallic objects, currents can be induced in these objects, leading to power loss

Answer 56

Induction Losses

Question 57

are non-propagating waves that exist in certain media where the signal frequency is lower than the cutoff frequency

Answer 57

Evanescent waves

Question 58

If the signal frequency is lower than the cutoff frequency of this dominant mode, the signal will propagate as an evanescent wave, which decays rapidly along the fiber.

Answer 58

dominant mode of propagation

Question 59

can occur when the harmonics of two signal wavelengths overlap with the frequency of a third wavelength. This can lead to the generation of new frequencies and distortion of the original signals

Answer 59

Four-Wave Mixing

Question 60

can be a significant source of noise and distortion, especially at high data rates

Answer 60

Four-Wave Mixing