Problem 3: (a) Calculate the attenuation of plane waves of 20 KHz and 10 GHz frequency propagating in salt water, fresh water and rock. Express the results in dB/m. The material

constants of the media are listed below: Medium Salt water Fresh water Rock Conductivity 4.5 10-² 2x10-3 Relative Permittivity 80 80 10 (b) What is the skin depth in rock at 20 KHz? How does it compare to that at 10 GHz?