An 800 KHz Radio Signal Is Detected at a Point

question 47

Multiple Choice

An 800 kHz radio signal is detected at a point 2.1 km distant from a transmitter tower.The electric field amplitude of the signal at that point is 800 mV/m.Assume that the signal power is radiated uniformly in all directions and that radio waves incident upon the ground are completely absorbed.The intensity of the radio signal at that point is closest to:

• A)8.5 × 10-4 W/m²
• B)1.2 × 10-3 W/m²
• C)1.7 × 10-3 W/m²
• D)6.0 × 10-4 W/m²
• E)4.2 × 10-4 W/m²