The electric field and magnetic field associated with an electromagnetic $(e.m.)$ wave,propagating along the $-z$ axis,can be represented by:

The electric field in $NC^{-1}$ of an electromagnetic wave is given by $E = 36 \sqrt{\pi} \sin(\omega t - kx)$. The average energy density of the electromagnetic wave due to the electric field is (Given: $\frac{1}{4 \pi \varepsilon_0} = 9 \times 10^9 \ Nm^2 C^{-2}$)

Due to the presence of an em-wave whose electric component is given by $E = 100 \sin(\omega t - kx) \ NC^{-1}$,a cylinder of length $200 \ cm$ holds a certain amount of em-energy inside it. If another cylinder of the same length but half the diameter of the previous one holds the same amount of em-energy,the magnitude of the electric field of the corresponding em-wave should be modified as:

The amplitude of the electric field associated with a light beam of intensity $\frac{15}{\pi} \text{ W m}^{-2}$ is (in $\text{ N C}^{-1}$)

In an electromagnetic wave,at an instant and at a particular position,the electric field is along the negative $z$-axis and the magnetic field is along the positive $x$-axis. Then the direction of propagation of the electromagnetic wave is

The wavelength of an electromagnetic wave radiated by a charge oscillating with a frequency of $1 \, \text{kHz}$ is ..... $km$.