Question

An electromagnetic wave with a peak magnetic field component of 3.20 × 10−7 T carries what average power per unit area? (μ0 = 4π × 10−7 T⋅m/A, ε0 = 8.85 × 10−12 C2/N⋅m2 and c = 3.00 × 108 m/s)

Answer 1

Answer:

The average power per unit area is 12.22 W/m²

Explanation:

Given that,

Peak magnetic field $B=3.20\times10^{-7}\ T$

We need to calculate the peak electric field

Using formula of electric filed

$E_{peak}=B_{peak}\times c$

Put the value into the formula

$E_{peak}=3.20\times10^{-7}\times3\times10^{8}$

$E_{peak}=96\ N/C$

We need to calculate the average power per unit area

Using formula of average power

$I=\dfrac{E_{max}^2}{2\mu_{0}c}$

Put the value into the formula

$I=\dfrac{96^2}{2\times4\pi\times10^{-7}\times3\times10^{8}}$

$I=12.22\ W/m^2$

Hence, The average power per unit area is 12.22 W/m²

Answer 2

Answer:

Explanation:

Average power per unit area =

I avg = c B₀² / 2μ₀

= 3 X 10⁸ X (3.2 X 10⁻⁷)² / 2 X 4π × 10⁻⁷

= 1.22 X 10

12 . 2 W / m²