Find the radiation resistance (Prob. 11.3) for the

Chapter 11, Problem 6P

(choose chapter or problem)

Problem 6P

Find the radiation resistance (Prob. 11.3) for the oscillating magnetic dipole in Fig. 11.8. Express your answer in terms of λ and b, and compare the radiation resistance of the electric dipole.

figure 11.8

Reference Prob. 11.3

Find the radiation resistance of the wire joining the two ends of the dipole. (This is the resistance that would give the same average power loss—to heat—as the oscillating dipole in fact puts out in the form of radiation.) Show that R = 790 (d/λ)2 Ω, where λ is the wavelength of the radiation. For the wires in an ordinary radio (say, d = 5 cm), should you worry about the radiative contribution to the total resistance?