MCQ in Transmission Fundamentals Part 9 | ECE Board Exam

This is the Multiple Choice Questions Part 9 of the Series in Transmission Fundamentals as one of the Communications Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies, Communications Books, Journals and other Communications References.

MCQ Topic Outline included in ECE Board Exam Syllabi

• MCQ in Transmission System
• MCQ in Transmission Medium
• MCQ in Velocity and Line Wavelength
• MCQ in Characteristics Impedance
• MCQ in Primary Line Constants and Propagation Constants
• MCQ in Standing Waves
• MCQ in Voltage Standing Wave Ratio
• MCQ in Telephone Lines and Cables
• MCQ in Wave Guides
• MCQ in Balanced and Unbalanced Lines
• MCQ in Twisted pair wire, Coaxial Cable
• MCQ in Decibel
• MCQ in Signal and Noise Fundamentals

Continue Practice Exam Test Questions Part 9 of the Series

⇐ MCQ in Transmission Fundamentals Part 8 | ECE Board Exam

Choose the letter of the best answer in each questions.

401. A (75 – j50)-ohm is connected to a coaxial transmission line of Zo = 75 ohms, at 10 GHz. The best method of matching consists of connecting

A. A short-circuited stub at the load

B. An inductive at the load

C. A capacitance at some specific distance from the load

D. A short-circuited stub at some specific distance from the load

402. The velocity factor of a transmission line

A. Depends on the dielectric constant of the material used

B. Increases in velocity along the transmission line

C. Is governed by the skin effect

D. Is higher for a solid dielectric than for air.

403. Impedance inversion may be obtained with

A. A short-circuited stub

B. An open-circuited stub

C. A quarter-wave line

D. A half-wave line

404. The most desirable reflection coefficient is

A. 0

B. 0.5

C. 1

D. Infinity

405. Short circuited stubs are preferred to open-circuited stub because the latter are

A. More difficult to make and connect

B. Made of a transmission line with different characteristic impedance

C. Liable to radiate

D. Incapable of giving a full range of reactance

406. For transmission-line load matching over a range of frequencies, it is best to use a

A. Balun

B. Broadband directional coupler

C. Double stub

D. Single stub of adjustable position

407. The main disadvantage of the two-hole directional coupler is

A. Low directional coupling

B. Poor directivity

C. High SWR

D. Narrow bandwidth

408. To couple a coaxial line to a parallel-wire line, it is best to use a

A. Slotted line

B. Balun

C. Directional coupler

D. Quarter-wave transformer

409. A short-circuited quarter-wavelength line acts like a

A. Parallel resonant circuit

B. Series resonant circuit

C. Oscillator

D. LC circuit

410. If the length of a short-circuited stub is less than a quarter-wavelength but greater than 0, the stub behaves as

A. Inductor

B. Capacitor

C. Resistor

D. Complex

411. The depth of penetration of current density resulting from skin effect

A. Skin depth

B. Wire depth

C. Line depth

D. Medium depth

412. Transmission line must be matched to the load to

A. Transfer maximum voltage to the load

B. Transfer maximum current to the load

C. Reduce the load current

D. Transfer maximum power to the load

413. Referred to the dielectric constant of a transmission line material

A. Inductance and capacitance

B. Velocity factor

C. Characteristic impedance

D. Propagation velocity

414. A transmission line containing of two conductors that have equal resistance per unit length

A. Unbalanced line

B. Open-wire line

C. Balanced line

D. Coaxial cable

415. Which of the following determines the characteristics of a transmission line?

A. Inductance

B. Capacitance

C. Physical dimension

D. Length

416. Category of UTP that was designed for data transmission rates up to 20 Mbps

A. Category 5e

B. Category 4

C. Category 5

D. Category 3

417. Level 2 or category 2 UTP cables comply with IBM’s _______ specification.

A. Type 1

B. Type 3

C. Type 2

D. Type 4

418. Level 3 or Category 3 UTP cables should have at least ____ twist per inch.

A. 1

B. 2

C. 3

D. 4

419. Which of the following is NOT a color code for Category 5 UTP?

A. Blue/white stripe and blue

B. Orange/white stripe and orange

C. Red/white stripe and red

D. Brown/white stripe and brown

420. Shielded-screen twisted-pair cable or SSTP is also known as ________.

A. Cat 5e

B. Cat 7

C. Cat 6

D. Cat 8

421. An open-circuited transmission line quarter wavelength long is equivalent to

A. Parallel resonant circuit

B. Series resonant circuit

C. Inductive

D. Capacitive

422. A short-circuited transmission line more than quarter-wavelength long but shorter than half wavelength is equivalent to _______.

A. Series resonant circuit

B. Inductive

C. Capacitive

D. Parallel resonant circuit

423. A short-circuited transmission line less than quarter-wavelength long.

A. Inductive

B. Capacitive

C. Parallel resonant circuit

D. Series resonant circuit

424. The quarter-wavelength transformer line acts as a transformer with a 1:1 turns ratio when the load resistance is with what relationship with the characteristic impedance of the quarter-wavelength transformer?

A. Equal

B. Less than

C. Greater than

D. None of these

425. The characteristic impedance of a microstrip is equal to _____ ohms.

A. 50 to 200

B. 25 to 50

C. 100 to 200

D. 50 to 75

426. The quarter-wavelength transformer line acts as a step down transformer when the load resistance is with what relationship with the characteristic impedance of the quarter-wavelength transformer?

A. Equal

B. Less than

C. Greater than

D. None of these

427. The typical value of the velocity factor of an open-wire transmission line is

A. 0.8

B. 0.7

C. 0.6

D. 0.9

428. If a transmission line is not terminated in its characteristic impedance, _______ will develop along the line.

A. Traveling waves

B. Standing waves

C. Surge impedance

D. Infinite impedance

429. If a load and a line have mismatched impedances, power not absorbed by the load will be _____.

A. Absorbed

B. Rejected

C. Reflected

D. Removed

430. Two wire line is usually operated in the:

a. Balanced mode

b. Unbalanced mode

c. High frequency

d. None of these

431. When the load impedance doesn’t not match the line impedance, part of the energy in the incident wave is ________ at the load.

a. Forwarded

b. Reflected

c. Same

d. None of these

432. In practice, the transmission lines are almost connected to antennas that have a _____.

a. Resistive load whose resistance is greater than the characteristic impedance of the line

b. Resistive load whose resistance is less than the characteristic impedance of the line

c. Resistive load at the resonant frequency

d. Capacitive load

433. When the transmission line is matched to the load, it

a. Transfers maximum current to the load

b. Transfers maximum voltage to the load

c. Transfers maximum power to the load

d. Reduces the load current

434. Conventional transmission media include

a. Twisted cable pair

b. Waveguide

c. Fiber optic cable

d. All of these

435. To couple a coaxial line to a parallel wire line, it is best to use a _____

a. Slotted line

b. Directional coupler

c. Balun

d. All of these

436. Impedance inversion may be obtained with

a. An open circuited stub

b. A short circuited stub

c. A quarterwave line

d. A half-wave line

437. To be properly matched, the ratio of maximum to minimum voltage along a transmission line should be equal to

a. 50

b. 10

c. 2

d. 1

438. When ZL ≠ Zo, the power sent down the line toward the load is called the

a. The incident power

b. The reflected power

c. The power dissipation

d. The carrier power

439. For transmission line load matching over a range of frequencies, it is best to use a

a. Balun

b. Broadband directional coupler

c. Double stub

d. Single adjustable stub

440. A short section of a transmission line, open or shorted that is used to match the impedance of the line to that of an antenna or transmitter.

a. Slotted line

b. Stub

c. Wavetrap

d. Lecher wire

441. The property of a material that determines how much electrostatic energy can be stored per unit volume when voltage is applied

a. Permeability

b. Magnetic effect

c. Capacitance

d. Permittivity

442. The value of the total opposition of the transmission media to the flow of electromagnetic field energy is called

a. Characteristic impedance

b. Velocity factor

c. Standing waves

d. Reflected waves

443. When mismatch is great, this power actually cause damage to the transmitter or the line itself.

a. The incident power

b. The reflected power

c. The power dissipation

d. The carrier power

444. What is the velocity factor for non-foam dielectric 50 or 75 ohm flexile coaxial cable such as RG 8, 11, 58 and 59?

a. 270

b. 0.10

c. 0.66

d. 0.30

445. The measure of the superiority of a material over a vacuum as a path for magnetic lines of force is

a. Permittivity

b. Permeability

c. Conductivity

d. Resistivity

446. The number of standing waves on the wire is equal to the length of the wire divided by a half wavelength. The principle which allows antennas to operate at different frequencies which are integral multiples of the fundamental frequency is called_______.

a. Harmonic operation

b. Decimonic operation

c. Electromagnetic reverberation

d. Asynchronous operation

447. A coax line has an attenuation of 2.4 dB per 100 ft. the attenuation for 2.75 ft. is _____ dB.

a. 2.4

b. 4.8

c. 3.3

d. 6.6

448. When a quarter wave stub is used to match a 600 ohm antenna to a line of 52 ohms, the impedance of the matching stub must be ____ ohms.

a. 176

b. 200

c. 150

d. 300

449. The characteristic impedance of a transmission line is determined by

a. Its length

b. Its height above ground

c. Its physical construction

d. The operating frequency

450. When the diameter of two conductors of a two-wire transmission line is held constant, the effect of decreasing the distance between the conductors is to

a. Decrease the impedance

b. Increase the surge impedance

c. Increase the radiation resistance

d. Decrease SWR

Questions and Answers in Transmission Fundamentals Series

Following is the list of multiple choice questions in this brand new series:

Complete List of MCQ in Communications Engineering per topic