An 800-KHz Sinusoidal Radio Signal Is Detected at a Point $\vec { E }$

Multiple Choice

An 800-kHz sinusoidal radio signal is detected at a point 6.6 km from the transmitter tower.The $\vec { E }$ field amplitude of the signal at that point is 0.780 V/m.Assume that the signal power is radiated uniformly in all directions and that radio waves incident upon the ground are completely absorbed.What is the amplitude of the $\vec { B }$ field of the signal at that point? (ε₀ = 8.85 × 10^-12 C²/N ∙ m²,c = 3.0 × 10⁸ m/s,μ₀ = 4π × 10^-7 T ∙ m/A)

A) 2.6 nT
B) 2.1 nT
C) 1.6 nT
D) 3.1 nT
E) 3.6 nT