Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric coaxial cable, assuming all other parameters are the same?

Q: Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric coaxial cable, assuming all other parameters are the same?

The correct answer is D: All these choices are correct. The correct answer is D: All these choices are correct. With other parameters held equal, a foam dielectric contains more air than a solid dielectric. That produces a higher velocity factor and lower dielectric loss, while the reduced amount of solid insulation also lowers the safe maximum operating voltage.

Previous Next

Deep Dive: E9F08

The correct answer is D: All these choices are correct. With other parameters held equal, a foam dielectric contains more air than a solid dielectric. That produces a higher velocity factor and lower dielectric loss, while the reduced amount of solid insulation also lowers the safe maximum operating voltage.

Why Other Answers Are Wrong

Option A: This statement is true, but it is not complete because the loss and velocity-factor statements are also true. Option B: This statement is true, but it is only one of the listed differences. Option C: This statement is true, but it is only one of the listed differences.

Exam Tip

Foam dielectric means less solid material: lower loss, higher velocity factor, and lower voltage rating.

Memory Aid

Foam: faster and lower loss, but lower voltage.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E9F

Reference: 2024-2028 Question Pool · E9 - Antennas and Transmission Lines

Key Concepts

foam dielectric coax velocity factor cable loss voltage rating

Official Pool Source

Question text and answer key are synchronized with the current NCVEC Extra Class pool and mapped to the E9F topic.