Question

The amplitude of electric field in a parallel light beam of intensity $4W{m}^{-2}$ is :

• A. $35.5N{C}^{-1}$
• B. $45.5N{C}^{-1}$
• C. $49.5N{C}^{-1}$
• D. $54.8N{C}^{-1}$

Answer 1

The correct option is A $35.5N{C}^{-1}$

$\begin{array}{c}{E}_0=\sqrt{\frac{2I}{{\in }_{0}c}}\\ =\sqrt{\left[\frac{2\times 4}{\left(8.85\times {10}^{-12}\times 3\times {10}^8\right)}\right]}\\ =35.5N/C\end{array}$

Hence,

option $\left(A\right)$ is correct answer.