Refractive index of glass is 1.5. Find the wavelength of a beam of light with a frequency of $${10^{14}}$$ Hz in glass. Assume velocity of light is $$3\,\, \times \,{10^8}$$ m/s in vacuum.

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 line-of-sight communication requires the transmit and receive antennas to face each other. If the transmit antenna is vertically polarized for best reception the receiver antenna should be

If the diameter of a $$\lambda /2$$ dipole antenna is increased from $$\lambda /100$$ to $$\lambda /50$$ then is