A radiation is emitted by


A radiation is emitted by $1000 \mathrm{~W}$ bulb and it generates an electric field and magnetic field at $\mathrm{P}$, placed at a distance of $2 \mathrm{~m}$. The efficiency of the bulb is $1.25 \%$. The value of peak electric field at $P$ is $x \times 10^{-1} \mathrm{~V} / \mathrm{m}$. Value of $x$ is_. (Rounded-off to the nearest integer)

$\left[\right.$ Take $\varepsilon_{0}=8.85 \times 10^{-12} \mathrm{C}^{2} \mathrm{~N}^{-1} \mathrm{~m}^{-2}, \mathrm{c}=3 \times 10^{8}$ $\left.\mathrm{ms}^{-1}\right]$


$\mathrm{I}_{\mathrm{avg}}=\frac{1}{2} \varepsilon_{0} \mathrm{E}_{0}^{2} \mathrm{C}$

$\frac{1.25}{100} \times \frac{1000}{4 \pi(2)^{2}}=\frac{1}{2} \times 8.85 \times 10^{-12} \times 3$

$\times 10^{8} \times \mathrm{E}_{0}^{2}$


$\therefore \mathrm{E}_{0}=13.689 \mathrm{~V} / \mathrm{m}$

$=136.89 \times 10^{-1} \mathrm{~V} / \mathrm{m}$

$\therefore x=136.89$

Rounding off to nearest integer



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