Transmission Line Applications: Matching Networks, Filters, and Antennas

Question 1

Which of the following is NOT a type of matching network used to match a load to a transmission line?

Accepted Answer

Low-pass filter

Answer

L-section

Answer

T-section

Answer

Pi-section

Question 2

Which of the following antenna types is characterized by its narrow bandwidth and directional radiation pattern?

Accepted Answer

Yagi-Uda antenna

Answer

Dipole antenna

Answer

Patch antenna

Answer

Horn antenna

Question 3

Which parameter of a transmission line determines the time delay of a signal propagating along the line?

Accepted Answer

Propagation constant

Answer

Inductance

Answer

Capacitance

Answer

Resistance

Question 4

What is the purpose of a stub in a transmission line application?

Accepted Answer

To terminate the line with a matched impedance

Answer

To create a resonant circuit

Answer

To filter out unwanted frequencies

Answer

To amplify the signal

Question 5

What is the purpose of using a directional coupler in a transmission line system?

Accepted Answer

To measure the power flowing in the line

Answer

To isolate one section of the line from another

Answer

To match the impedance of the line to a load

Answer

To generate a standing wave pattern

Question 6

How does the directivity of an antenna affect the area it covers?

Accepted Answer

Higher directivity leads to a smaller coverage area.

Answer

Higher directivity results in a larger coverage area.

Answer

Directivity has no impact on the coverage area.

Answer

Coverage area is independent of antenna directivity.

Question 7

An antenna possesses a directivity of 10 dBi and an effective aperture of 200 cm². Calculate the antenna's gain.

Accepted Answer

11 dBi

Answer

1 dBi

Answer

100 dBi

Answer

20 dBi

Question 8

How do antennas generate electromagnetic waves?

Accepted Answer

Oscillating electrical currents in the antenna structure produce varying electric and magnetic fields that propagate as electromagnetic waves.

Answer

Electrostatic charges accumulate on the antenna surface, emitting electromagnetic waves.

Answer

Mechanical vibrations of the antenna structure generate electromagnetic waves.

Answer

Chemical reactions within the antenna material release electromagnetic energy.

Question 9

A transmission line with a characteristic impedance of 50 ohms is terminated with a load impedance of 100 ohms. What is the reflection coefficient at the load?

Accepted Answer

0.25

Answer

0.5

Answer

0.75

Answer

1.0

Question 10

The primary purpose of a matching network in a transmission line system is to:

Accepted Answer

Maximize power transfer by minimizing reflections

Answer

Increase the system's bandwidth

Answer

Reduce the line's capacitance

Answer

Enhance the antenna's efficiency

Question 11

Which filter type allows signals within a specific frequency band to pass through while blocking others?

Accepted Answer

Band-pass filter

Answer

Low-pass filter

Answer

High-pass filter

Answer

Band-reject filter

Question 12

In a lossless transmission line, the characteristic impedance is equal to:

Accepted Answer

The square root of inductance divided by capacitance

Answer

The line's resistance

Answer

The line's inductance

Answer

The product of resistance and inductance

Question 13

The function of a quarter-wave transformer in a transmission line system is to:

Accepted Answer

Match impedance between two lines

Answer

Reduce signal reflections

Answer

Introduce a phase shift

Answer

Increase the bandwidth of the system

Question 14

Which antenna type is commonly employed for long-distance radio signal transmission and reception?

Accepted Answer

Parabolic antenna

Answer

Dipole antenna

Answer

Yagi antenna

Answer

Horn antenna

Question 15

The primary factor determining an antenna's radiation pattern is:

Accepted Answer

A combination of all the above

Answer

Antenna's physical structure

Answer

Operating frequency

Answer

Polarization of electromagnetic waves

Question 16

The distinction between a lumped circuit and a distributed circuit lies in:

Accepted Answer

Lumped circuits have concentrated elements, while distributed circuits have elements spread along the line

Answer

Distributed circuits have concentrated elements, while lumped circuits have elements spread along the line

Answer

Lumped circuits have constant parameters, while distributed circuits have variable parameters

Answer

Distributed circuits have constant parameters, while lumped circuits have variable parameters

Question 17

Which transmission line parameter is expressed in ohms?

Accepted Answer

Characteristic impedance

Answer

Propagation constant

Answer

Velocity factor

Answer

Input impedance

Question 18

The relationship between wavelength and frequency in an electromagnetic wave traveling through a transmission line is:

Accepted Answer

Wavelength is inversely proportional to frequency

Answer

Wavelength is directly proportional to frequency

Answer

Wavelength is independent of frequency

Answer

Frequency is directly proportional to wavelength

Question 19

Which filter type is characterized by its ability to block a specific frequency range while allowing other frequencies to pass?

Accepted Answer

Band-stop filter

Answer

Low-pass filter

Answer

High-pass filter

Answer

Band-pass filter

Question 20

Which of the following is a primary application of Smith charts?

Accepted Answer

Analyzing impedance matching

Answer

Characterizing frequency response

Answer

Calculating power dissipation

Answer

Visualizing antenna radiation patterns

Question 21

The characteristic impedance (Z0) of a transmission line is determined primarily by:

Accepted Answer

Conductor size and spacing, as well as dielectric properties

Answer

Voltage and current

Answer

Length and capacitance

Answer

Frequency and wavelength

Question 22

Which of the following factors does NOT affect the characteristic impedance of a transmission line?

Accepted Answer

Conductor temperature

Answer

Frequency

Answer

Dielectric constant

Answer

Conductor spacing

Question 23

A standing wave ratio (SWR) close to 1 indicates:

Accepted Answer

Good impedance matching

Answer

Partial impedance matching

Answer

Low impedance mismatch

Answer

High impedance mismatch

Question 24

Which of the following is a common application of microwave transmission lines?

Accepted Answer

Radar systems

Answer

Telephone lines

Answer

Power distribution

Answer

Audio cables

Question 25

A transmission line with low attenuation has:

Accepted Answer

Low signal loss

Answer

Low capacitance

Answer

High signal loss

Answer

High impedance

Question 26

What is the primary function of a low-pass filter in a transmission line system?

Accepted Answer

To attenuate high-frequency signals

Answer

To amplify high-frequency signals

Answer

To attenuate low-frequency signals

Answer

To amplify low-frequency signals

Question 27

Which antenna type is commonly employed for transmitting and receiving radio signals?

Accepted Answer

Dipole antenna

Answer

Horn antenna

Answer

Parabolic antenna

Answer

Patch antenna

Question 28

What is the input impedance of a quarter-wave transformer when it is properly matched?

Accepted Answer

Z0

Answer

Z0/2

Answer

Infinite

Answer

2Z0

Question 29

Which of the following is NOT a standard characteristic impedance value for a coaxial cable?

Accepted Answer

500 ohms

Answer

50 ohms

Answer

300 ohms

Answer

75 ohms

Question 30

When a transmission line is perfectly matched, what is its standing wave ratio (SWR)?

Accepted Answer

1

Answer

2

Answer

0

Answer

Infinite

Question 31

Which instrument is primarily used to measure the voltage standing wave ratio (VSWR) on a transmission line?

Accepted Answer

VSWR meter

Answer

Voltmeter

Answer

Ohmmeter

Question 32

Precisely define the characteristic impedance of a transmission line.

Accepted Answer

The impedance that the line presents to a signal at any point along its length

Answer

The impedance of the generator connected to the line

Answer

The impedance of the load connected to the line

Question 33

What is the primary function of a filter used in a transmission line system?

Accepted Answer

To selectively pass or reject certain frequency ranges

Answer

To match impedance

Answer

To amplify the signal

Answer

To reduce noise

Question 34

In a lossless transmission line, the characteristic impedance is determined by the relationship between which two parameters?

Accepted Answer

Inductance and capacitance per unit length

Answer

Resistance and capacitance per unit length

Answer

Inductance and resistance per unit length

Answer

Capacitance and conductance per unit length

Question 35

What is the primary purpose of using a stub in a transmission line system?

Accepted Answer

To create a localized resonance or reactance

Answer

To increase the bandwidth

Answer

To reduce reflections

Answer

To improve impedance matching

Question 36

Which type of transmission line is best suited for high-power applications due to its ability to handle large amounts of current?

Accepted Answer

Coaxial cable

Answer

Optical fiber

Answer

Twisted pair cable

Answer

Microstrip line

Question 37

How does the skin depth affect the resistance of a transmission line?

Accepted Answer

It increases the effective resistance at high frequencies due to current concentration near the conductor's surface

Answer

It decreases the effective resistance at high frequencies due to reduced current flow

Answer

It has no significant impact on the resistance

Answer

It increases the effective resistance at low frequencies

Question 38

Which parameter determines the amount of power lost in a transmission line due to resistive and dielectric losses?

Accepted Answer

Attenuation constant

Answer

Characteristic impedance

Answer

Velocity of propagation

Answer

Phase constant

Question 39

What is the primary reason for grounding a transmission line system?

Accepted Answer

To ensure electrical safety and protect against hazardous voltages

Answer

To reduce power losses

Answer

To enhance bandwidth

Answer

To improve signal quality

Question 40

In a transmission line system, what is the primary purpose of a filter?

Accepted Answer

To selectively allow or reject specific frequencies, enabling frequency filtering

Answer

To boost the signal strength, providing amplification

Answer

To convert alternating current (AC) to direct current (DC), facilitating power conversion

Answer

To match impedance, ensuring efficient signal transfer

Question 41

In the context of a lossless transmission line, what mathematical expression defines its characteristic impedance?

Accepted Answer

Square root of inductance per unit length divided by capacitance per unit length

Answer

Inductance per unit length divided by capacitance per unit length

Answer

Resistance per unit length divided by inductance per unit length

Question 42

In a transmission line system, which factor primarily influences the magnitude of the standing wave ratio (SWR)?

Accepted Answer

Impedance mismatch between the transmission line and the load, causing reflections

Answer

Frequency of the transmitted signal, determining wavelength

Answer

Length of the transmission line, affecting signal propagation

Question 43

In a transmission line system, what is the primary function of a balun?

Accepted Answer

To facilitate the conversion between balanced and unbalanced lines, ensuring signal compatibility

Answer

To filter out unwanted frequencies, removing noise

Answer

To amplify the signal, boosting its strength

Answer

To match impedance, optimizing signal transfer

Question 44

In the context of transmission lines, which characteristic determines the maximum power that can be transmitted without causing signal distortion?

Accepted Answer

Power handling capacity, which specifies the maximum power level a transmission line can handle without compromising signal integrity

Answer

Inductance, which influences the signal's propagation speed

Answer

Voltage rating, indicating the maximum voltage a transmission line can withstand

Question 45

What is the primary function of a matching network in a transmission line system?

Accepted Answer

To maximize power transfer by eliminating reflections.

Answer

To amplify the signal strength.

Answer

To filter out unwanted frequencies.

Question 46

Which type of transmission line filter is commonly used to block specific frequency bands?

Accepted Answer

Band-stop filter

Answer

High-pass filter

Answer

Low-pass filter

Answer

Band-pass filter

Question 47

A quarter-wave transformer is an example of what type of matching network?

Accepted Answer

Impedance matching network

Answer

Power amplifier

Answer

Frequency multiplier

Question 48

A transmission line filter is typically characterized by its:

Accepted Answer

Passband and stopband frequencies

Answer

Voltage gain

Answer

Power dissipation

Answer

Current gain

Question 49

Which of the following is NOT a common type of antenna used in transmission line applications?

Accepted Answer

Diode antenna

Answer

Monopole antenna

Answer

Dipole antenna

Answer

Yagi antenna

Question 50

What is the primary factor influencing the radiation pattern of an antenna?

Accepted Answer

Antenna geometry and size

Answer

Environmental conditions

Answer

Input power

Answer

Signal frequency

Question 51

The concept of standing wave ratio (SWR) is used to evaluate:

Accepted Answer

The degree of impedance mismatch on a transmission line

Answer

The signal strength at the receiver

Answer

The efficiency of the antenna

Question 52

A transmission line with a characteristic impedance of 50 ohms is connected to a load with an impedance of 100 ohms. What type of matching network would be most suitable to minimize reflections?

Accepted Answer

A quarter-wave transformer

Answer

A stub matching network

Answer

A low-pass filter

Answer

A band-pass filter

Question 53

In a typical transmission line system, where would you expect to see the highest voltage standing wave ratio (SWR)?

Accepted Answer

At the point of impedance mismatch

Answer

At the center of the transmission line

Answer

At the antenna

Answer

At the transmitter