An 800 kHz radio signal is detected at a point 6.6 km distant from a transmitter tower.The electric field amplitude of the signal at that point is 780 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 magnetic field amplitude of the signal at that point,in nT,is closest to:
A)2.6
B)2.1
C)1.6
D)3.1
E)3.6

Question

Quizplus · Accepted Answer

The correct answer is A.The magnetic field amplitude can be calculated using the formula:B = E / cwhere:B is the magnetic field amplitude in teslasE is the electric field amplitude in volts per meterc is the speed of light in meters per secondPlugging in the given values, we get:B = 780 mV/m / (3 x 10^8 m/s) = 2.6 nT

An 800 KHz Radio Signal Is Detected at a Point