assignment

Question details:

(20%) We know the surface of the earth is a good reflector at AM radio frequencies (50 to
200 kHz), yet a poor reflector in the visible (1014 Hz). At what RF frequency will the electrical
properties of the earth transition from conductive to dielectric? Explain your result. (Use ? =
5x10-3 S/m, ur = 1, and er = 8 for the earth.) (Hint: consider reflection from the ground and/or
attenuation into the ground.)