This is the Multiples Choice Questions Part 8 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.

### Online Questions and Answers Topic Outline

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

### MCQs in Transmission Fundamentals Series

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

**Transmission Fundamentals MCQs**

**MCQs from Number 1 – 50**Answer key:

**PART I**

**MCQs from Number 51 – 100**Answer key:

**PART II**

**MCQs from Number 101 – 150**Answer key:

**PART III**

**MCQs from Number 151 – 200**Answer key:

**PART IV**

**MCQs from Number 201 – 250**Answer key:

**PART V**

**MCQs from Number 251 – 300**Answer key:

**PART VI**

**MCQs from Number 301 – 350**Answer key:

**PART VII**

**MCQs from Number 351 – 400**Answer key:

**PART VIII**

**MCQs from Number 401 – 450**Answer key:

**PART IX**

**MCQs from Number 451 – 500**Answer key:

**PART X**

### Continue Practice Exam Test Questions Part VIII of the Series

351. A coaxial cable with two layers of foil insulation and two layers of braided shielding.

- A. Quad shielding
- B. Double shielding
- C. Triple shielding
- D. Shielding

352. A type of coaxial cable that has a tubular outer conductor surrounds the center conductor coaxially and the insulating material is air.

- A. Rigid air coaxial cable
- B. Gas-filled coaxial cable
- C. Solid coaxial cable
- D. Flexible cable

353. If the length of an open-circuited stub is less than quarter-wavelength but greater than 0, the stub behaves as

- A. Inductor
- B. Capacitor
- C. Resistor
- D. Complex

354. Type of coaxial cable where the outer conductor is braided, flexible, and coaxial to the center conductor.

- A. Gas-filled coaxial cable
- B. Rigid air coaxial cable
- C. Solid flexible coaxial cable
- D. Flexible cable

355. A 50-ohm coax is connected to a 73-ohm antenna. The SWR is

- A. 0.685
- B. 1
- C. 1.46
- D. 2.92

356. Defined as the impedance seen looking at an infinitely long line or the impedance seen looking into a finite length of the line that is terminated in a purely resistive load with the resistance equal to the characteristic impedance of the line.

- A. Input impedance
- B. Surge impedance
- C. Output impedance
- D. Circuit impedance

357. Determine the characteristic impedance for an air dielectric two-wire parallel transmission line with a D/r ratio of 12.22

- A. 150 ohms
- B. 120 ohms
- C. 75 ohms
- D. 300 ohms

358. Determine the characteristic impedance for an RG-59A coaxial cable with the following specifications: d = 0.025 inches, D = 0.15 inches, and dielectric constant of 2.23

- A. 120 ohms
- B. 72 ohms
- C. 150 ohms
- D. 75 ohms

359. Determine the characteristic impedance for an RG-59A coaxial cable with the following specifications: L=0.118 uH/ft and C = 21 pF/ft

- A. 150 ohms
- B. 72 ohms
- C. 75 ohms
- D. 100 ohms

360. It is used to express the attenuation or signal loss and the phase shift per unit length of the transmission line.

- A. Propagation coefficient
- B. Propagation constant
- C. Propagation factor
- D. Any of these

361. For matched condition, what is the relationship of load and characteristic impedance?

- A. Greater than
- B. Less than
- C. Equal
- D. Impossible to say

362. It is defined simply as the ratio of the actual velocity of propagation of an electromagnetic wave through a given medium to the velocity of propagation through a vacuum or free space.

- A. Velocity factor
- B. Velocity propagation
- C. Index of refraction
- D. Phase delay

363. It is simply the permittivity of the material

- A. Permittivity
- B. Insulation constant
- C. Dielectric constant
- D. Resistivity

364. For a given length of RG 8A/U coaxial cable with distributed capacitance of 96.6 pF/m, a distributed inductance of 241.56 nH/m, and a relative dielectric constant of 2.3, determine the velocity of propagation.

- A. 1.07 x 10^8 m/s
- B. 2.3 x 10^7 m/s
- C. 3.28 x 10^8 m/s
- D. 2.07 x 10^8 m/s

365. For a given length of RG 8A/U coaxial cable with distributed capacitance of 96.6 pF/m, a distributed inductance of 241.56 nH/m, and a relative dielectric constant of 2.3, determine the velocity factor

- A. 1.2
- B. 0.66
- C. 0.7
- D. 0.5

366. If the length of an open-circuited stub is greater than quarter-wavelength but less than half-wavelength, the stub behaves as

- A. Inductor
- B. Capacitor
- C. Resistor
- D. Complex

367. Delay line is a function of what two parameters?

- A. Resistance and capacitance
- B. Resistance and susceptance
- C. Inductance and resistance
- D. Inductance and capacitance

368. How is the time delay calculated in a coaxial cables with a dielectric constant of 0.66?

- A. 0.56 sec
- B. 0.67 sec
- C. 0.45 sec
- D. 1.2 sec

369. Three feet is one wavelength at a frequency of

- A. 100 MHz
- B. 164 MHz
- C. 300 MHz
- D. 328 MHz

370. When current flows through a conductor, the loss introduced as a function of resistance and current is called _______.

- A. Inductance loss
- B. Conductor loss
- C. Voltage loss
- D. Skin effect

371. For maximum absorption of power at the antenna, the relationship between the characteristic impedance of the line Zo and the load impedance ZL should be

- A. Zo = ZL
- B. Zo > ZL
- C. Zo < ZL
- D. Zo = 0

372. The ratio of the AC resistance and the DC resistance.

- A. Impedance ratio
- B. Susceptance ratio
- C. Resistance ratio
- D. Conductance ratio

373. The difference in potential between two conductors of a metallic transmission line causes ______.

- A. Conductor loss
- B. Dielectric heating
- C. Radiation loss
- D. Corona

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

- A. Inductor
- B. Capacitor
- C. Resistor
- D. Complex

375. If the separation between the conductors in a metallic transmission line is an appreciable fraction of a wavelength, the electrostatic and electromagnetic fields that surround the conductor cause the line to act as if it were an antenna and transfer energy to any nearby material. This energy radiated is called ______.

- A. Radiation loss
- B. Power loss
- C. Coupling loss
- D. Corona

376. The minimum voltage along a transmission line is 260 V, while the maximum is 390 V. The SWR is

- A. 0.67
- B. 1.0
- C. 1.2
- D. 1.5

377. It occurs whenever a connection is made to or from a transmission line or when two sections of transmission line are connected together.

- A. Power loss
- B. Coupling loss
- C. Radiation loss
- D. Resistance loss

378. Which of the following is not a common transmission line impedance?

- A. 50 ohms
- B. 75 ohms
- C. 120 ohms
- D. 300 ohms

379. It is a luminous discharge that occurs between the two conductors of a transmission line when the difference in potential between them exceeds the breakdown voltage of a dielectric insulator.

- A. Resistance loss
- B. Corona
- C. Radiation loss
- D. Power loss

380. Voltage that propagates down the load.

- A. Reflected voltage
- B. Standing wave ratio
- C. Incident voltage
- D. Reflection voltage

381. Voltage that propagates from the load towards the source.

- A. Reflected voltage
- B. Standing wave ratio
- C. Reflection coefficient
- D. Incident voltage

382. A transmission line with no reflected power.

- A. Flat
- B. Resistive
- C. Non resonant line
- D. Any of these

383. It is a vector quantity that represents the ratio of reflected voltage to incident voltage or the reflected current and the incident current

- A. Reflection coefficient
- B. Reactive load diagram
- C. Standing wave ratio
- D. Traveling waves

384. With a mismatched line, two electromagnetic waves traveling in opposite direction, present on the line on the same time.

- A. Standing wave ratio
- B. Reflection coefficient
- C. Standing waves
- D. Traveling waves

385. The two traveling waves sets up an interference pattern called _______.

- A. Standing wave ratio
- B. Reflection coefficient
- C. Standing waves
- D. Traveling waves

386. It is defined as the ratio of the maximum voltage to the minimum voltage or the maximum current to the minimum current of a standing wave in a transmission line.

- A. Standing wave ratio
- B. Normalized impedance
- C. Reflection coefficient
- D. Any of these

387. For a transmission line with an incident voltage of 5V and a reflected voltage of 3V, determine the reflection coefficient.

- A. 0.4
- B. 0.6
- C. 0.5
- D. 0.7

388. A ratio expressing the percentage of incident voltage reflected on a transmission line is known as the

- A. Velocity factor
- B. Standing wave ratio
- C. Reflection coefficient
- D. Line efficiency

389. There is an impedance inversion in every ______.

- A. Half wavelength
- B. Quarter wavelength
- C. Full wavelength
- D. Three-eights of a wavelength

390. The characteristic impedance of a transmission line does not depend upon its

- A. Length
- B. Conductor diameter
- C. Conductor spacing
- D. None of these

391. ______ are used to match transmission lines to purely resistive loads whose resistance is not equal to the characteristic impedance of the line.

- A. Stub
- B. Slotted lines
- C. Quarter-wavelength transformer
- D. Short circuited lines

392. To match a transmission line with a reactive load _______.

- A. Use stub matching
- B. Use a slotted line
- C. Used a Q-section
- D. Use an open circuited lines

393. A technique that can be used to locate an impairment in metallic cable.

- A. TDR
- B. Wattmeter
- C. Voltmeter
- D. SWR meter

394. A pulse is transmitted down a cable that has a velocity of propagation of 0.8c. The reflected signal is received 1us later. How far down the cable is the impairment?

- A. 240 m
- B. 15 m
- C. 60 m
- D. 120 m

395. Using TDR, a transmission line impairment is located 3000m from the source. For a velocity propagation of 0.9 c, determine the time elapsed from the beginning of the pulse to the reception of the echo

- A. 11.11 us
- B. 10.12 us
- C. 22.22 us
- D. 21.14 us

396. A flat conductor separated from a ground plane by an insulating dielectric material.

- A. Stripline
- B. Waveguide
- C. Microstrip
- D. Coaxial cable

397. A flat conductor sandwich between two ground planes.

- A. Stripline
- B. Waveguide
- C. Microstrip
- D. Coaxial cable

398. Indicate the false statement. The SWR on a transmission line is infinity; the line is terminated in

- A. A short circuit
- B. A complex impedance
- C. An open circuit
- D. A pure reactance

399. The most commonly used transmission line is a

- A. Two-wire balance line
- B. Singe wire
- C. Three-wire line
- D. Coax

400. A short-circuited half-wavelength line acts like a

- A. Parallel resonant circuit
- B. Series resonant circuit
- C. Oscillator
- D. LC circuit