Question

The average magnetic energy density of an electromagnetic wave of wavelength l travelling in free space is given by

• A. $\frac{B^2}{2\lambda }$
• B. $\frac{B^2}{2{\mu }_0}$
• C. $\frac{B^2}{{\mu }_0\lambda }$
• D. $\frac{B}{{\mu }_0\lambda }$

Answer 1

Answer: (B)

The average magnetic energy density of an electromagnetic wave travelling in free space is
$u_B=\frac{B^2}{2{\mu }_0}$