A magnetic dipole antenna is used to detect an electromagnetic wave. The antenna

Question

A magnetic dipole antenna is used to detect an electromagnetic wave. The antenna is a coil of 50 turns with radius 5.6 cm. The EM wave has frequency 870 kHz, electric field amplitude 0.48 V/m, and magnetic field amplitude 1.60 10-9 T. (a) For best results, should the axis of the coil be aligned with the electric field of the wave, or with the magnetic field, or with the direction of propagation of the wave? electric field magnetic field direction of propagation (b) Assuming it is aligned correctly, what is the amplitude of the induced emf in the coil? (Since the wavelength of this wave is much larger than 5.6 cm, it can be assumed that at any instant the fields are uniform within the coil.) mV (c) What is the amplitude of the emf induced in an electric dipole antenna of length 5.6 cm aligned with the electric field of the wave? mV

Explanation / Answer

It seems that Faraday's law (ref.) applies.
V = N*d(BA)/dt = NBA*2pi*f = 50*1.6E-9*pi*0.056^2*2pi*8.7E5 = 4.4636352E-03 V

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