Question

The maximum magnitude of the magnetic field of an electromagnetic wave is 13.5 μΤ. (3396) Problem 3: 笄What is the average total energy density (in μ1m3) of this electromagnetic wave? Assume the wave is propagating in vacuum.

Answer 1

The average total energy density of this electromagnetic wave is
`72.5\ \mu\ J/m^3`.

Step-by-step explanation:

Given that,

Magnetic field
`B = 13.5\mu T`

We need to calculate the average total energy density

Using formula of energy density

`Energy\ density =(S)/(c)`....(I)

Where, S = intensity

c = speed of light

We know that,

The intensity is given by

`S = (B^2c)/(2\mu_(0))`

Put the value of S in equation (I)

`Energy\ density =((B^2c)/(2\mu_(0)))/(c)`

`Energy\ density = ((13.5*10^(-6))^2)/(2*4\pi*10^(-7))`

`Energy\ density = 0.0000725\ J/m^3`

`Energy\ density = 72.5*10^(-6)\ J/m^3`

`Energy\ density = 72.5\ \mu\ J/m^3`

Hence, The average total energy density of this electromagnetic wave is
`72.5\ \mu\ J/m^3`.