An electromagnetic wave propagating through a vacuum is described by $E = E_0 \sin(kx - \omega t)$ and $B = B_0 \sin(kx - \omega t)$. Which of the following equations is true?

The dimensions of $\frac{1}{{\mu _0}{\varepsilon _0}}$ are .......... .

The velocity of electromagnetic radiation in a medium of permittivity $\varepsilon_{0}$ and permeability $\mu_{0}$ is given by

$A$ laser beam of pulse power $10^{12} \ W$ is focused on an object area of $10^{-4} \ cm^2$. The energy flux in $W/cm^2$ at the point of focus is:

Given below are two statements: one is labelled as Assertion $(A)$ and other is labelled as Reason $(R).$
Assertion $(A):$ Electromagnetic waves carry energy but not momentum.
Reason $(R):$ Mass of a photon is zero.
In the light of the above statements,choose the most appropriate answer from the options given below:

If a plane electromagnetic wave has electric field oscillations of frequency $3 \text{ GHz}$, then the wavelength of the wave is (speed of light in vacuum $= 3 \times 10^8 \text{ m/s}$) (in $\text{ m}$)