Question

The sunlight reaching the earth has maximum electric field of $810V/m$. What is the maximum magnetic field in this light?

• A. $2.7\mu T$
• B. $1.8\mu T$
• C. $0.9\mu T$
• D. $0.3\mu T$

Answer 1

The correct option is A $2.7\mu T$



Electric and magnetic field components are given by
$E=E_0\sin \omega t$ and $B=B_0\sin \omega t$
where $B_0=\frac{E_0}{c}$ and $c=\frac{1}{\sqrt{{\mu }_0{ϵ}_0}}$

$\therefore B_0=\frac{E_0}{c}=\frac{810}{3\times {10}^8}$
$=27\times {10}^{-7}T=2.7\times {10}^{-6}=2.7\mu T$