What Is the Maximum Value of the Magnetic Field at a Distance

Multiple Choice

What is the maximum value of the magnetic field at a distance of $2.5 \mathrm {~m}$ from a light bulb that radiates $100 \mathrm {~W}$ of single-frequency sinusoidal electromagnetic waves uniformly in all directions? ( $\left. \varepsilon _ { 0 } = 8.85 \times 10 ^ { - 12 } \mathrm { C } ^ { 2 } / \mathrm { N } \cdot \mathrm { m } ^ { 2 } , \mu _ { 0 } = 4 \pi \times 10 ^ { - 7 } \mathrm {~T} \cdot \mathrm { m } / \mathrm { A } , c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$

A) $0.80 \mu \mathrm { T }$
B) $0.40 \mu \mathrm { T }$
C) $0.10 \mu \mathrm { T }$
D) $0.50 \mu \mathrm { T }$
E) $0.60 \mu \mathrm { T }$