Radio waves and visible light in vacuum have

Calculate the electric and magnetic fields produced by the radiation coming from a $100\; W$ bulb at a distance of $3\; m$. Assume that the efficiency of the bulb is $2.5\%$ and it is a point source.

$A$ plane electromagnetic wave travels in vacuum along the $z$-direction. What can you say about the directions of its electric and magnetic field vectors? If the frequency of the wave is $30 \; MHz$,what is its wavelength in $m$?

The energy associated with the electric field is $(U_E)$ and with the magnetic field is $(U_B)$ for an electromagnetic wave in free space. Then

Given below are two statements:
Statement $I$: $A$ time-varying electric field is a source of a changing magnetic field and vice-versa. Thus,a disturbance in an electric or magnetic field creates $EM$ waves.
Statement $II$: In a material medium,the $EM$ wave travels with speed $v = \frac{1}{\sqrt{\mu_{0} \varepsilon_{0}}}$.
In the light of the above statements,choose the correct answer from the options given below:

The electric field of a plane electromagnetic wave is given by $\vec E = E_0 \hat i \cos(kz) \cos(\omega t)$. The corresponding magnetic field $\vec B$ is then given by: