Ham Radio General Class Test Ham Radio General Class Test Antennas and Feed Lines Questions and Answers 3

Question 1

What is the approximate characteristic impedance of common RG-213 coaxial cable?

Accepted Answer

50 ohms

Answer

75 ohms

Answer

93 ohms

Answer

300 ohms

Question 2

Which antenna type consists of a driven element and one or more parasitic elements to provide directional gain?

Accepted Answer

A Yagi-Uda antenna

Answer

A random wire antenna

Answer

An isotropic radiator

Answer

A folded dipole

Question 3

What happens to the bandwidth of a dipole antenna as the diameter of the wire is increased?

Accepted Answer

The bandwidth increases

Answer

The bandwidth decreases

Answer

The bandwidth stays the same

Answer

The resonant frequency doubles

Question 4

What is the velocity factor of a feed line?

Accepted Answer

The speed at which a signal travels through the line compared to the speed of light

Answer

The rate at which signal strength decreases per foot

Answer

The maximum frequency the cable can carry

Answer

The ratio of impedance to capacitance per foot

Question 5

What is a common cause of feed line failure in an outdoor coaxial cable installation?

Accepted Answer

Water intrusion into the cable or connectors

Answer

Using too short a cable run

Answer

Operating below the cable's rated frequency

Answer

Connecting to a resonant antenna

Question 6

What is the purpose of an antenna tuner (transmatch) in an amateur radio station?

Accepted Answer

To match the transceiver output impedance to the feed line impedance presented at the shack

Answer

To increase the power output of the transmitter

Answer

To eliminate all SWR on the feed line

Answer

To change the resonant frequency of the antenna