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

RG-213 is a 50-ohm coaxial cable commonly used in amateur radio transmitting applications.

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 Yagi-Uda antenna uses a driven element along with parasitic directors and reflectors to create a directional radiation pattern with gain.

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

Increasing the conductor diameter of a dipole lowers the Q of the antenna, which results in a wider usable bandwidth.

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

Velocity factor is the ratio of the speed of signal propagation in the feed line to the speed of light in free space, typically expressed as a percentage.

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

Moisture entering coaxial cable or its connectors causes increased loss, corrosion, and eventual failure of the feed line.

Ham Radio General Class Test Practice Test

Ham Radio General Class Test Practice Test

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