The electromagnetic radiation which has the smallest wavelength are

If the ratio of relative permeability and relative permittivity of a uniform medium is $$1: 4$$. The ratio of the magnitudes of electric field intensity $$(E)$$ to the magnetic field intensity $$(H)$$ of an EM wave propagating in that medium is (Given that $$\sqrt{\frac{\mu_0}{\varepsilon_0}}=120 \pi$$):

The property which is not of an electromagnetic wave travelling in free space is that:

In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of $$2.0 \times 10^{10} \mathrm{~Hz}$$ and amplitude $$48 ~\mathrm{Vm}^{-1}$$. Then the amplitude of oscillating magnetic field is : (Speed of light in free space $$=3 \times 10^{8} \mathrm{~m} \mathrm{~s}^{-1}$$ )