E9F01

What is the velocity factor of a transmission line?

  1. The velocity of the wave in the transmission line divided by the velocity of light in a vacuum

E9F02

What determines the velocity factor in a transmission line?

  1. Dielectric materials used in the line

E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

  1. Electrical signals move more slowly in a coaxial cable than in air

E9F04

What is the typical velocity factor for a coaxial cable with solid polyethylene dielectric?

  1. 0.66

E9F05

What is the physical length of a coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz? (Assume a velocity factor of 0.66.)

  1. 3.5 meters

E9F06

What is the physical length of a parallel conductor feed line that is electrically one-half wavelength long at 14.10 MHz? (Assume a velocity factor of 0.95.)

  1. 10 meters

E9F07

What characteristic will 450-ohm ladder line have at 50 MHz, as compared to 0.195-inch-diameter coaxial cable (such as RG-58)?

  1. Lower loss

E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

  1. Velocity factor

E9F09

What would be the physical length of a typical coaxial transmission line that is electrically one-quarter wavelength long at 7.2 MHz? (Assume a velocity factor of 0.66)

  1. 6.9 meters

E9F10

What kind of impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

  1. An inductive reactance

E9F11

What kind of impedance does a 1/8-wavelength transmission line present to a generator when the line is open at the far end?

  1. A capacitive reactance

E9F12

What kind of impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

  1. A very low impedance

E9F13

What kind of impedance does a 1/4-wavelength transmission line present to a generator when the line is shorted at the far end?

  1. A very high impedance

E9F14

What kind of impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

  1. A very low impedance

E9F15

What kind of impedance does a 1/2-wavelength transmission line present to a generator when the line is open at the far end?

  1. A very high impedance

E9F16

What is the primary difference between foam-dielectric coaxial cable as opposed to solid-dielectric cable, assuming all other parameters are the same?

  1. A. Reduced safe operating voltage limits
  2. B. Reduced losses per unit of length
  3. C. Higher velocity factor
  4. D. All of these answers are correct

 

NEXT

Go To TOC