Question

The magnetic field in a travelling electromagnetic wave has a peak value of $20\text{nT}$. The peak value of electric field strength is

• A. $12\text{V/m}$
• B. $3\text{V/m}$
• C. $6\text{V/m}$
• D. $9\text{V/m}$

Answer 1

The correct option is C $6\text{V/m}$

Given:
Peak value of magnetic field, $B_0=20\text{nT}$

As, $E_0=c{B}_0$

Where, $c$ is the speed of light in vacuum.

$\Rightarrow E_0=(3\times {10}^8{\text{ms}}^{-1})\times (20\times {10}^{-9}\text{T})$

$\Rightarrow E_0=6\text{V/m}$

Hence, option $\left(C\right)$ is correct.