c
 વિદ્યુત ચુંબકીય તરંગો ની તીવ્રતા \(\,{\text{I}}\,\, = \,\,\frac{{{{\text{P}}_{{\text{av}}}}}}{{{\text{4}}\pi {{\text{r}}^{\text{2}}}}}\,\, = \,\,\frac{{E_m^2}}{{2{\mu _0}c}}\)

\({E_m}\, = \,\,\,\sqrt {\frac{{{\mu _0}c{P_{av}}}}{{2\pi {r^2}}}} \,\,\, = \,\,\,\sqrt {\frac{{(4\pi \,\, \times \,{{10}^{ - 7}})\,\, \times \,\,(3\,\, \times \,\,{{10}^8})\,\, \times \,\,800}}{{2\pi \,\, \times \,\,{{(3.5)}^2}}}} \,\, = \,\,62.6\,\,V/m\)

 વિદ્યુત ચુંબકીય ક્ષેત્ર ની મહતમ કિમત \( = \,\,{{\text{B}}_m}\,\, = \,\,\frac{{{E_m}}}{c}\,\, = \,\,\frac{{62.6}}{{3\,\, \times \,\,{{10}^8}}}\,\, = \,\,2.09\,\, \times \,\,{10^{ - 7}}\,\,T\)