Question

In an electromagnetic wave in free space the root mean square value of the electric field is `E_(rms)=6 V//m`. The peak value of the magnetic field is
A. `1.41xx10^-8T`
B. `2.83xx10^-8T`
C. `0.70xx10^-8T`
D. `4.23xx10^-8T`

Answer 1

Correct Answer - b
Here, `E_(rms)=6V//m, or (E_0)/(sqrt2)=6 or E_0=6sqrt2 V//m`
As `E_0=cB_0`
or `B_0=(E_0)/c=(6sqrt2)/(3xx10^8)=2sqrt2xx10^-8T`
`=2.83xx10^-8T`