Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Electrical Engineering


This paper is devoted to a study of resonance in magnetically coupled, tuned circuits, the primary having impressed on it a sinusoidal e.m.f. and containing capacity, inductance and resistance, the secondary circuit being the same as the primary except that the e.m.f. is induced by the primary. Two such circuits are represented in figure 1. The ordinary radio receiving or broadcasting se consists fundamentally of two such circuits. In the receiving set the e.m.f. in the primary is received from the waves in the ether, the ariel and ground being similar to the generator connections as show in the figure. The broadcasting set is almost the opposite of the receiving set. IN receiving and broadcasting, the thing of importance is that the current particularly in the secondary, be a maximum at some definite wave length that is some definite frequency. The first thing taken up is the symbols used and then the general equations for current in the type of circuits used. When simple circuit, such as number 1 in figure 1, is taken and the current, squared plotted as ordinates and the frequency as abscissas, a curve like those shown in figure 3 are obtained, but when another circuit, such as number 2 in figure 1, is brought near, the curves begin to show two peaks instead of one, as shown by figures 4 to 9. The figures raise the questions as to what frequencies will give a maximum value of current, that is a peak in the cure: what values of K will give one peak and what values will give two peaks, first in the curve for the primary and second in the curve for the secondary; what conditions will make the two peaks in the primary curve equal, the two peaks in the secondary curve equal.

Library of Congress Subject Headings

Electric Circuits


Includes bibliographical references (page 22)



Number of Pages



South Dakota State College


No Copyright - Non-Commercial Use Only