Out of the following options,which one can be used to produce a propagating electromagnetic wave?

The electric field component of an electromagnetic wave in vacuum is given as $\vec E = 3\cos(1.8y + 5.4 \times 10^8 t)\hat i$. Its direction of propagation and wavelength are:

$A$ radiation is emitted by a $1000 \, W$ bulb and it generates an electric field and magnetic field at point $P$, placed at a distance of $2 \, m$. The efficiency of the bulb is $1.25 \%$. The value of the peak electric field at $P$ is $x \times 10^{-1} \, V/m$. The value of $x$ is (rounded off to the nearest integer).
[Take $\varepsilon_{0} = 8.85 \times 10^{-12} \, C^2 N^{-1} m^{-2}, c = 3 \times 10^8 \, m/s$]

In fog, photographs of the objects taken with infrared radiations are more clear than those obtained during visible light because

The relative permittivity of distilled water is $81$. The velocity of light in it will be $....\times 10^{7} \text{ m/s}$. (Given $\mu_{r} = 1$) (in $.33$)

For which of the following media will the wave propagation occur without experiencing attenuation?