$5 \%$ of the power of a $100 \, W$ bulb is converted to visible radiation. The average intensity of visible radiation at a distance of $10 \, m$ from the bulb is .......... $W/m^2$.

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

For an $EM$ wave,the electric and magnetic fields are $300 \ V m^{-1}$ and $7.9 \ A m^{-1}$ respectively. The maximum rate of energy flow is, (in $W m^{-2}$)

Consider three quantities $x = E/B$,$y = \sqrt{1/(\mu_0 \varepsilon_0)}$ and $z = l/RC$. Here,$l$ is the length of a wire,$C$ is capacitance,and $R$ is resistance. All other symbols have standard meanings. Which of the following statements is correct?

The electric field intensity produced by the radiation coming from a $100 \, W$ bulb at a distance of $3 \, m$ is $E$. The electric field intensity produced by the radiation coming from a $60 \, W$ bulb at the same distance is $\sqrt{\frac{x}{5}} E$. The value of $x$ is ......... .

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.