Radio waves and visible light in vacuum have

Assume a bulb of efficiency $2.5\%$ as a point source. The peak value of the electric field produced by the radiation coming from a $100\, W$ bulb at a distance of $3\, m$ is approximately.....$V\,m^{-1}$.

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 $\text{ m}$)

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

The electric field of a plane electromagnetic wave is given by: $E_y = 69 \sin[0.6 \times 10^3 x - 1.8 \times 10^{11} t] \text{ V/m}$. The expression for the magnetic field associated with this electromagnetic wave is . . . . . . $T$.

Give the relation between vacuum permittivity $(\epsilon_{0})$, vacuum permeability $(\mu_{0})$, and the speed of light $(c)$.