In an electromagnetic wave,the electric field and magnetising field are $100\,V\,m^{-1}$ and $0.265\,A\,m^{-1}$ respectively. The maximum energy flow is.......$W\,m^{-2}$.

The power radiated from a linear antenna of length $l$ is proportional to (Given,$\lambda =$ wavelength of the wave):

$A$ long straight wire of resistance $R$,radius $a$,and length $l$ carries a constant current $I$. The Poynting vector for the wire will be

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

For a $GPS$ navigation to track a mobile device,we use :-

This question has Statement $-1$ and Statement $-2.$ Of the four choices given after the Statements,choose the one that best describes the two Statements.
Statement $-1:$ Short wave transmission is achieved due to the total internal reflection of the $e-m$ wave from an appropriate height in the ionosphere.
Statement $-2:$ Refractive index of the ionosphere is independent of the frequency of $e-m$ waves.