The reciprocal of the square root of the dielectric constant of the material used to separate the conductors in a transmission line gives the ____________ of the line:

The speed at which radio frequency energy travels through a transmission line is always less than the speed of light in a vacuum. This reduction in speed depends directly on the insulating material, or dielectric, used between the conductors. Mathematically, the velocity factor is calculated as 1 divided by the square root of the dielectric constant of the material. Therefore, the reciprocal of the square root of the dielectric constant precisely defines the velocity factor of the transmission line. Other options like impedance or VSWR involve different formulas and physical dimensions, whereas this specific mathematical relationship applies strictly to the speed of signal propagation.