If $\vec{E}$ and $\vec{B}$ are the electric field and magnetic field vectors of an electromagnetic wave respectively,then what is the direction of propagation of the electromagnetic wave?

$A$ plane electromagnetic wave is incident on a plane surface of area $A$ normally,and is perfectly reflected. If energy $E$ strikes the surface in time $t$,then the average pressure exerted on the surface is ($c=$ speed of light).

Which of the following is/are the property/properties of a monochromatic electromagnetic wave propagating in the free space?
$1$. Electric and magnetic fields will have a phase difference $\frac{\pi}{2}$.
$2$. The energy of the wave is distributed equally between electric and magnetic fields.
$3$. The pressure exerted by the wave is the product of its speed and energy density.
$4$. The speed of the wave is equal to the ratio of the magnetic field to the electric field.

The amplitude of the electric field in a parallel beam of plane electromagnetic waves of intensity $53.1 \ W \ m^{-2}$ is (Permittivity of free space $\epsilon_0 = 8.85 \times 10^{-12} \ C^2 \ N^{-1} \ m^{-2}$) (in $N \ C^{-1}$)

The pressure exerted by an electromagnetic wave of intensity $I \ (W/m^2)$ on a non-reflecting surface is [$c$ is the velocity of light].

The quantities $x = \frac{1}{\sqrt{\mu_{0} \varepsilon_{0}}}$,$y = \frac{E}{B}$,and $z = \frac{l}{CR}$ are defined,where $C$ is capacitance,$R$ is resistance,$l$ is length,$E$ is electric field,$B$ is magnetic field,and $\varepsilon_{0}, \mu_{0}$ are free space permittivity and permeability respectively. Then: