| 释义 |
Ohm's law
[see ohm2.]
1. Electr. The law that the strength of a constant electric current in a circuit is proportional to the electromotive force divided by the resistance of the circuit, and that the potential difference between any two points of it is proportional to the resistance between them. (The name was formerly used of some related principles also.)
Propounded by Ohm in Die galvanische Kette, mathematisch bearbeitet (1827).
1850Phil. Mag. XXXVII. 463 (heading) On a deduction of Ohm's laws, in connexion with the theory of electro-statics. 1863Rep. Brit. Assoc. Adv. Sci. 1862 i. 127 The first relation is a direct consequence of Ohm's Law. 1867Phil. Mag. XXXIII. 321 (heading) On one of Ohm's laws relating to an insulated circuit. 1910Encycl. Brit. IX. 182/2 This result..obtained by Cavendish in January 1781, that the current varies in direct proportion to the electromotive force, was really an anticipation of the fundamental law of electric flow, discovered independently by G. S. Ohm in 1827, and since known as Ohm's Law. 1921W. S. Ibbetson Motor & Dynamo Control iv. 131 Generally speaking, A.C. circuits do not obey Ohm's law. 1973J. W. Gardner New Frontiers in Electricity vii. 138 Superconductors constitute a very dramatic violation of Ohm's law.
2. Acoustics. The law that a complex musical sound is heard as the sum of a number of distinct pure tones into which the sound can be analysed by Fourier's theorem.
Propounded by Ohm in Ann. d. Physik (1843) LIX. 513, and called Ohm's Regel by Helmholtz in Die Lehre von den Tonempfindungen (1863) ii. 54.
1875A. J. Ellis tr. Helmholtz' On Sensations of Tone ii. 51 Every motion of the air..which corresponds to a composite mass of musical tones, is, according to Ohm's law, capable of being analysed into a sum of simple pendular vibrations, and to each such single simple vibration corresponds a simple tone, sensible to the ear. 1924Wilkinson & Gray Mechanism of Cochlea i. 14 Ohm's Law is a generalisation from the results of experiment. 1974S. E. Gerber Introductory Hearing Sci. vi. 134 Ohm's law has generated over a century of research, largely aimed at demonstrating its limitations. Ibid., When tones of relatively low intensity which differ considerably in frequency are presented together, they are perceived as two distinct tones, in accordance with Ohm's law. |