A plane wave in free space with
$$\overrightarrow E = \left( {\sqrt \pi } \right)\left( {10.0\,\widehat x + 11.8\,\widehat y} \right)\exp \left[ {j\left( {4\pi \times {{10}^8}\,t - k\,z} \right)} \right]$$
where $$\widehat x$$ and $$\widehat y$$ are unit vectors in the $$x$$- and $$y$$-directions respectively is incident normally on a semi-infinite block of ice as shown in Fig. For ice, $$\mu = {\mu _0},\,\,\,\sigma = 0$$ and $$\varepsilon = 9{\varepsilon _0}\left( {1 - j0.001} \right)$$.

(a) Calculate the average power density associated with the incident wave.

(b) Calculate the skin depth in ice.

(c) Estimate the average power density at a distance of 5 times the skins depth in the ice block, measured from the interface.

A transmitting antenna radiates 251 W isotropically. A receiving antenna, located 100m away from the transmitting antenna, has an effective aperture of 500 cm². The total power received by the antenna is

Identify which one of the following will NOT satisfy the wave equation.

Indicate which one of the following modes do NOT exist in a rectangular resonant cavity.