What is the speed of electromagnetic energy traveling through air?

The speed of electromagnetic energy, or electromagnetic waves such as light, in a vacuum is approximately 186,000 miles per second. When these waves travel through air, their speed is nearly the same, as air has a very low refractive index compared to a vacuum. This speed is a fundamental constant in physics known as the speed of light, represented as 'c', which is crucial for various applications in electronics, telecommunications, and physics. Thus, option B accurately reflects the commonly accepted speed of electromagnetic energy traveling through air, solidifying its status as the correct choice. Understanding this value is essential for calculations in physics and electronics, particularly when dealing with signal propagation and communications technology.