$TV$ waves have a wavelength range of $1-10 \,meter$. Their frequency range in $MHz$ is
$30-300$
$3-30$
$300-3000$
$3-3000$
The electric field and magnetic field components of an electromagnetic wave going through vacuum is described by
$E _{ x }= E _0 \sin ( kz -\omega t )$
$B _{ y }= B _0 \sin ( kz -\omega t )$
Then the correct relation between $E_0$ and $B_0$ is given by
In a certain region uniform electric field $E$ and magnetic field $B$ are present in the opposite direction. At the instant $t = 0,$ a particle of mass $m$ carrying a charge $q$ is given velocity $v_o$ at an angle $\theta ,$ with the $y$ axis, in the $yz$ plane. The time after which the speed of the particle would be minimum is equal to
The electric field associated with an em wave in vacuum is given by $\vec{E}=\hat{i} 40 \cos \left(k z-6 \times 10^{8} t\right)$ where $E, x$ and $t$ are in $volt/m,$ meter and seconds respectively. The value of wave vector $k$ is....$ m^{-1}$
A TV tower has a height of 100 m. The average population density around the tower is 1000 per $km^2$. The radius of the earth is $6.4 \times {10^6}$m. the population covered by the tower is
A plane electromagnetic wave of frequency $25\; \mathrm{GHz}$ is propagating in vacuum along the $z-$direction. At a particular point in space and time, the magnetic field is given by $\overrightarrow{\mathrm{B}}=5 \times 10^{-8} \hat{\mathrm{j}}\; \mathrm{T}$. The corresponding electric field $\overrightarrow{\mathrm{E}}$ is (speed of light $\mathrm{c}=3 \times 10^{8}\; \mathrm{ms}^{-1})$