The magnitude of the Poynting vector of a planar electromagnetic wave has an average value of 0.724 W/m2. What is the maximum value of the magnetic field in the wave? (c=3.0×108m/s, μ0=4π×10−7T⋅m/A, ε0=8.85×10−12C2/N⋅m2)

The maximum value of the magnetic field in the wave is

Explanation:

Given that,

Average value of pointing vector = 0.724 W/m²

We need to calculate the magnetic field

Using formula of pointing vector

The average value of pointing vector

We know that,

Put the value of in equation (II)

substitute the value in the formula

The maximum value of the magnetic field in the wave is

this could be newton#'s law of cooling. the cooling curve is exponential