If electric permittivity and magnetic permeability of the medium are respectively $$\varepsilon $$ and $$\mu $$, then the velocity (C_m) of the electromagnetic wave in the medium is given by:

A. Focal length B. Flying height C. Ground elevation D. None of these

A. Absorption by the dissolved material B. Absorption by the suspended particulate matter C. Scattering by the suspended particulate matter D. All of these

A. 0.4 - 0.7 μm B. 0.5 mm to 1 μm C. 0.7 - 1.3 μm D. 0.7 to 14 μm

A. $$\frac{\pi }{4}$$ B. $$\frac{\pi }{2}$$ C. $$\pi $$ D. $$\frac{{3\pi }}{2}$$