How are microwaves produced?

The electric field in an electromagnetic wave is given by $E = (50 \, NC^{-1}) \sin \omega(t - x/c)$. The energy contained in a cylinder of volume $V$ is $5.5 \times 10^{-12} \, J$. The value of $V$ is $...... \, cm^3$ (given $\epsilon_0 = 8.8 \times 10^{-12} \, C^2 N^{-1} m^{-2}$).

An $EM$ wave propagating in $x$-direction has a wavelength of $8\,mm$. The electric field vibrating in $y$-direction has a maximum magnitude of $60\,Vm^{-1}$. Choose the correct equations for electric and magnetic fields if the $EM$ wave is propagating in vacuum.

Electromagnetic waves are transverse in nature is evident by

$A$ plane $EM$ wave travelling in vacuum along $z$-direction is given by $\vec E = E_0 \sin(kz - \omega t) \hat i$ and $\vec B = B_0 \sin(kz - \omega t) \hat j$.
$(i)$ Evaluate $\int \vec E \cdot d\vec l$ over the rectangular loop $1234$ shown in the figure.
$(ii)$ Evaluate $\int \vec B \cdot d\vec s$ over the surface bounded by loop $1234$.
$(iii)$ Use $\int \vec E \cdot d\vec l = -\frac{d\phi_E}{dt}$ to prove $\frac{E_0}{B_0} = c$.
$(iv)$ By using a similar process and the equation $\int \vec B \cdot d\vec l = \mu_0 I + \mu_0 \epsilon_0 \frac{d\phi_E}{dt}$,prove that $c = \frac{1}{\sqrt{\mu_0 \epsilon_0}}$.

For plane electromagnetic waves propagating in the $z$-direction,which one of the following combinations gives the correct possible direction for $\vec{E}$ and $\vec{B}$ fields respectively?