Measurements of the torques and forces between two short single layer cylindrical coils carrying undamped currents alternating at radio frequencies showed variations with the frequency of the current oscillation not predicted from the classical formulas of Maxwell and others. When the current in the coils and the angle between the planes of the coils were maintained constant, the torque between the two coils connected in series, with the currents in the same sense, was found to remain approximately constant as the frequency of the current increased from 60 to 0.3x101 cycles per second, but when the frequency increased from 0.3x105 to 1.5xl06 cycles per second, the torque increased with the frequency, in some cases being more than doubled. The rate of increase of the torque with the frequency decreased to zero as the angle between the planes of the coils increased from 10° to 90°, and remained zero within the error of experiment as the angle changed from 90 ° to 180 °, i. e., when the currents were in the opposite sense.
Proceedings of the Iowa Academy of Science
©1923 Iowa Academy of Science, Inc.
Parlin, W. A.
"The Torques and Forces between Short Cylindrical Coils Carrying Undamped Alternating Currents of Radio Frequency,"
Proceedings of the Iowa Academy of Science, 30(1), 84-86.
Available at: https://scholarworks.uni.edu/pias/vol30/iss1/27