Technician exam question T7C11

WhyFoam-dielectric coaxial cable has less loss per foot than solid-dielectric cable. Foam dielectric contains trapped air pockets that have less signal-absorbing material per foot than a fully solid dielectric, giving foam-dielectric coax lower loss per foot at a given size, answer C. Foam is actually more susceptible to moisture contamination (A), not less, and dielectric type mainly affects loss rather than voltage breakdown (B) or a cable's nominal impedance match to 50 ohms (D), which is set by the cable's geometry, not whether the dielectric is foam or solid.