Q. For EM wave prorogating along $x$-axis, $E_{\max}\ = 30\ {Vm}^{- 1}.$ what is maximum value of magnetic field?
A) 10$^{-7}$ T
B) 10$^{-8}$ T
C) 10$^{-9}$ T
D) 10$^{-6}$ T
Explanation
(a) The amplitude of the electric and magnetic fields in free space are related by $\frac{E_{0}}{B_{0}}\ = c$
Here, $E_{0} = \ 30\ {Vm}^{- 1},\ c = 3\ \times 10^{8}\ {ms}^{- 1}$
$\therefore\ \ \ \ \ \ \ B_{0} = \frac{E_{0}}{c}\ = \ \frac{30}{3\ \times \ 10^{8}}\ = \ 10^{- 7}\ T$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.