According to the theoretical study of radiation from a linear antenna,the power radiated is proportional to $[\lambda = \text{wavelength}]$

The electric field of a plane electromagnetic wave is given by $\overrightarrow{E} = E_{0} \frac{\hat{i}+\hat{j}}{\sqrt{2}} \cos (kz+\omega t)$. At $t=0$,a positively charged particle is at the point $(x, y, z) = (0, 0, \frac{\pi}{k})$. If its instantaneous velocity at $t=0$ is $v_{0} \hat{k}$,the force acting on it due to the wave is

$A$ radar sends an electromagnetic signal with an electric field $E_{0} = 2.25\,V/m$ and a magnetic field $B_{0} = 1.5 \times 10^{-8}\,T$,which strikes a target on the line of sight at a distance of $3\,km$ in a medium. After that,a part of the signal (echo) reflects back towards the radar with the same velocity and along the same path. If the signal was transmitted at time $t_{0}$ from the radar,then after how much time (in $\times 10^{-5}\,s$) will the echo reach the radar?

$A$ microwave and an ultrasonic sound wave have the same wavelength. Their frequencies are in the ratio (approximately):

Match the following List-$I$ with the List-$II$:

List-$I$	List-$II$
$(A)$ Gauss's law	$(I)$ Surface charge density
$(B)$ Faraday's law	$(II)$ Electric charge and energy conservation
$(C)$ Ampere's law	$(III)$ Change in magnetic flux
$(D)$ Kirchhoff's law	$(IV)$ Change in electric flux
	$(V)$ Total electric flux

The electromagnetic flux from the Sun reaching the Earth is $10^3 \ W m^{-2}$. What is the power incident on a roof of dimensions $6 \ m \times 30 \ m$?