eorem on the integration of differential forms to obtain Maxwell’s equations in integral form:</p>
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\[\oint\limits _ {\eth V}\vec {D}\vec {dS} = 4\pi\int\limits_V\rho {dV},\]</div>
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\[\oint\limits _ {\eth S}\vec {H}\vec {dl} =\frac {4\pi} {c}\int\limits_S\vec {\jmath}\vec {dS}.\]</div>
<p>Find <span class="math notranslate nohighlight">\(D_r\)</span> for a cylindrical beam of radius <span class="math notranslate nohighligh