Electromagnetic Waves

The magnitude of the magnetic field is related to as:
And the Poynting vector magnitude is:
Substituting the given values, we find the correct values.

Radio waves in the frequency range of 3 MHz to 30 MHz are typically reflected by the ionosphere, leading to sky wave propagation.

The loss tangent is given by:
where is the conductivity, is the angular frequency, and is the permittivity.
- If Loss Tangent , the material is a lossless dielectric.
- If Loss Tangent is moderate, it represents a lossy dielectric.
- If Loss Tangent is very high, the material is a good conductor.
Thus, the Loss Tangent determines whether a medium behaves as free space, a dielectric, or a conductor.