Two biggest changes from one coax size to another are?

• A. Impedance and shielding
• B. Diameter and color code
• C. Flexibility and temperature
• D. DC resistance and attenuation

Answer: (D)

The thing that changes the most when you move from one coax size to another is how much signal is lost along the line and the resistance of the conductor at DC. The center conductor’s cross-sectional area grows with a larger coax, so its DC resistance drops. Lower DC resistance means less I²R loss, which directly reduces the amount of signal lost along a given length, i.e., lower attenuation. Attenuation itself is influenced by both conductor losses and dielectric losses, but the change in conductor size is the primary driver of the difference you’ll see between coax sizes. Other factors like impedance, shielding, or color coding don’t shift as dramatically with size alone, and things like flexibility or temperature are more about construction. So the two biggest changes you’ll observe between coax sizes are DC resistance and attenuation.