If a $10 \ W$ bulb emits electromagnetic waves uniformly in all directions,then the intensity of light at a distance $0.5 \ m$ from the source is nearly (in $W \ m^{-2}$)

If an electromagnetic wave is propagating in the $x$-direction and the magnetic field $\vec{B}$ at any instant is in the $z$-direction,then at that instant,the electric field $\vec{E}$ will be in the ........ direction.

An electromagnetic wave travelling in $x$-direction is described by field equation $E_y = 300 \sin \omega \left( t - \frac{x}{c} \right)$. If the electron is restricted to move in $y$-direction only with speed of $1.5 \times 10^6 \text{ m/s}$, then the ratio of maximum electric and magnetic forces acting on the electron is . . . . . . .

If $\vec{E}$ and $\vec{B}$ represent electric and magnetic field vectors of an electromagnetic wave,the direction of propagation of the wave is along

The electromagnetic waves travel in a medium at a speed of $2.0 \times 10^{8} \ m/s$. The relative permeability of the medium is $1.0$. The relative permittivity of the medium will be (in $.25$)

For a plane electromagnetic wave propagating in the $x$-direction,which one of the following combinations gives the correct possible directions for the electric field $(E)$ and magnetic field $(B)$ respectively?