Q. The energy associated with electric field is $(U_E)$ and with magnetic field is $(U_B)$ for an electromagnetic wave in free space. Then :

Solution:

Average energy density of magnetic field,
$u_{B} = \frac{B_{0}^{2}}{2 \mu_{0}} , B_{0} $ is maximum value of magnetic field.
Average energy density of electric field,
$u_{E} = \frac{\varepsilon_{0} \in^{2}_{0}}{2}$
now, $ \in_{0} =CB_{0} , C^{2} = \frac{1}{\mu_{0} \in_{0} } $
$ u_{E} = \frac{\in_{0}}{2} \times C^{2} B^{2}_{0} $
$ = \frac{\in_{0}}{2} \times\frac{1}{\mu_{0} \in_{0}} \times B^{2}_{0} = \frac{B^{2}_{0}}{2 \mu_{0}} = u_{B}$
$ u_{E} = u_{B} $
since energy density of electric & magnetic field is same, energy associated with equal volume will be equal.
$ u_{E} = u_{B} $

You must select option to get answer and solution

Questions from JEE Main 2019

Physics Most Viewed Questions

6. The spectrum of an oil flame is an example for ...........

KCET 2010 Dual Nature Of Radiation And Matter