If the electric field intensity associated with a uniform plane electromagnetic wave traveling in a perfect dielectric medium is given by

$$E\left( {z,\,t} \right) = \,10\,\cos \left( {2\pi \times {{10}^7}\,\,t - 0.1\,\,\pi z} \right)\,$$ volt/m, the velocity of the traveling wave is

Medium $$1$$ has the electrical permittivity $${\varepsilon _1} = 1.5\,\,{\varepsilon _0}\,\,\,F/m$$ and occupies the region to left of $$x = 0$$ plane. Medium $$2$$ has the electrical permittivity $${\varepsilon _2} = 2.5\,\,{\varepsilon _0}\,\,\,F/m$$ and occupies the region to the right of $$x = 0$$ plane. If $${E_1}$$ in medium $$1$$ is $${E_1} = \left( {2\,{u_x} - 3\,{u_y} + 1\,{u_z}} \right)$$ volt/m, then $${E_2}$$ in medium $$2$$ is

A plane wave is characterized by $$$\overrightarrow E = \left( {0.5\mathop x\limits^ \cap + \mathop y\limits^ \cap \,{e^{j\pi /2}}} \right){e^{j\omega t - jkz}}.$$$

This wave is

Distilled water at $${25^ \circ }C$$ is characterized by $$\sigma = 1.7 \times {10^{ - 4}}$$ mho/m and $$ \in = 78{ \in _0}$$ at a frequency of $$3 GHz$$. Its loss tangent $$\tan \delta $$ is