A plane electromagnetic wave of frequency $50\, MHz$ travels in free space along the positive $x-$ direction. At a particular point in space and time, $\vec E = 6.3\,\hat j\,V/m$ . The corresponding magnetic field $\vec B$, at that point will be
$18.9 \times {10^{ - 8}}\,\hat kT$
$2.1 \times {10^{ - 8}}\,\hat kT$
$6.3 \times {10^{ - 8}}\,\hat kT$
$18.9 \times {10^{ 8}}\,\hat kT$
A carbon dioxide laser emits sinusoidal electro-magnetic wave that travels in vacuum in the negative $x-$ direction. The wavelength is $10.6\,\mu $ and $\vec E$ fields is parallel to $z-$ axis, with $E_{max} = 1.5 \times 10^6\, M\, v/m$. Then vector equations for $\vec E$ and $\vec B$ as a function of time and position are
When $EM$ wave propagates through vacuum then
In an $EMW$ phase difference between electric and magnetic field vectors $\vec E$ and $\vec B$ is
If ${\varepsilon _0}$ and ${\mu _0}$ are respectively, the electric permittivity and the magnetic permeability of free space. $\varepsilon $ and $\mu $ the corresponding quantities in a medium, the refractive index of the medium is
A long straight wire of resistance $R$, radius $a $ and length $ l$ carries a constant current $ I.$ The Poynting vector for the wire will be