What physical quantity is the same for $X$-rays of wavelength $10^{-10} \; m$,red light of wavelength $6800 \; \mathring{A}$,and radio waves of wavelength $500 \; m$?

$A$ 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 $\varepsilon_{0} = 8.85 \times 10^{-12} \, C^2 N^{-1} m^{-2}, c = 3 \times 10^8 \, m/s$]

Choose the correct statement.

For a plane electromagnetic wave,the magnetic field at a point $x$ and time $t$ is $\overrightarrow{ B }( x , t ) = [1.2 \times 10^{-7} \sin (0.5 \times 10^{3} x + 1.5 \times 10^{11} t) \hat{ k }] \text{ T}$. The instantaneous electric field $\overrightarrow{ E }$ corresponding to $\overrightarrow{ B }$ is: (speed of light $c = 3 \times 10^{8} \text{ m/s}$)

In an $EM$ wave propagating along the $X-$ direction,the magnetic field oscillates at a frequency of $3 \times 10^{10} \, Hz$ along the $Y-$ direction and has an amplitude of $10^{-7} \, T$. The expression for the electric field will be:

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?