A plane electromagnetic wave propagating in free space in incident normally on a large slab of loss-less, non-magnetic, dielectric material with $$\varepsilon > {\varepsilon _0}$$. Maxima and minima are observed when the electric field is measured in front of the slab. The maximum electric field is found to be $$5$$ times the minimum field. The intrinsic impedance of the medium should be

The phase velocity of an electromagnetic wave propagating in a hollow metallic rectangular waveguide in the $$T{E_{10}}$$ mode is

Consider a lossless antenna with a directive gain of + 6 dB. If 1 m W of power is fed to it the total power radiated by the antenna will be

The impurity commonly used for realizing the base region of a silicon n-p-n transistor is