Question

6. Poynting vector, ( S=frac{P}{4 pi r^{2}}=frac{c B_{max }^{2}}{2 mu_{0}} )
( Rightarrow mathrm{B}_{mathrm{max}}=sqrt{frac{2 mathrm{P} mu_{0}}{4 pi mathrm{r}^{2} mathrm{c}}}=sqrt{frac{2 times 15 times 10^{-7}}{(2)^{2}(3 times 10)^{8}}}=5 times 10^{-8} mathrm{T} )

# A point source of power 15 W is placed at a certain point in the space. The amplitude of magnetic field at a distance of 2 meter from source is : (1) 5 x 10-8 T (2) 6 × 10-8 T (3) 10 x 10-8 T x 10-8 T

Solution