EM waves question

Question

Assume that a lamp radiate power P uniformly in all directions. What is the magnitude of electric field strength at a distance r from the lamp??

 This is a question from electromagnetic waves physics class 12

Answer 1

I = \(\frac{1}{2}\)\(\epsilon_0 \epsilon^2_0\)

I =  \(\frac{P}{AC}\)

\(\frac{P}{C\times4\pi R^2}\) = \(\frac{1}{2}\)\(\epsilon_0 \epsilon^2_0\)

\(\epsilon^2_0\) = \(\frac{P}{2\pi \epsilon_0R^2C}\)

\(\epsilon_0 \) = \(\sqrt\frac{P}{2\pi \epsilon_0 R^2 C}\)

Comments

Thank you so much