Respuesta :
Answer:
The magnetic field strength, the energy density, and the power flow per unit area are [tex]2.35\times10^{-7}\ T[/tex], [tex]4.396\times10^{-8}\ J/m^3[/tex] and 13.18 W/m².
Explanation:
Given that,
Electromagnetic wave strength E= 70.5 V/m
(I). We need to calculate the magnetic field strength
Using formula of Electromagnetic wave strength
[tex]c= \dfrca{E}{B}[/tex]
[tex]B=\dfrac{E}{c}[/tex]
[tex]B=\dfrac{70.5 }{3\times10^{8}}[/tex]
[tex]B=2.35\times10^{-7}\ T[/tex]
(II). We need to calculate the energy density
Using formula of energy density
[tex]\mu_{total}=\mu_{E}+\mu_{B}[/tex]
[tex]\mu_{total}=\dfrac{1}{2}\epsilon_{0}E^2+\dfrac{1}{2}\dfrac{B^2}{\mu_{0}}[/tex]
[tex]\mu_{total}=\dfrac{1}{2}\times8.85\times10^{-12}\times(70.5)^2+\dfrac{1}{2}\times\dfrac{(2.35\times10^{-7})^2}{4\pi\times10^{-7}}[/tex]
[tex]\mu_{total}=4.396\times10^{-8}\ J/m^3[/tex]
(III). We need to calculate the power flow per unit area
Using formula of poynting vector
[tex]S=\dfrac{1}{\mu_{0}}EB[/tex]
Put the value into the formula
[tex]S=\dfrac{1}{4\pi\times10^{-7}}\times70.5\times2.35\times10^{-7}[/tex]
[tex]S=13.18\ W/m^2[/tex]
Hence, The magnetic field strength, the energy density, and the power flow per unit area are [tex]2.35\times10^{-7}\ T[/tex], [tex]4.396\times10^{-8}\ J/m^3[/tex] and 13.18 W/m².
