| 释义 |
Hall2 Physics.
The name of Edwin H. Hall (1855–1938), American physicist, used attrib. to designate an effect discovered by him and various quantities associated therewith (see quot. 1958).
1902Hall effect [see electric potential s.v. electric a. 2 b]. 1922Glazebrook Dict. Appl. Physics II. 468/2 The effect of a magnetic field upon the electrical conductivity of metals, first discovered by Lord Kelvin in 1856 and known as the Hall effect, is very marked in the case of bismuth wire or plates. 1940Chambers's Techn. Dict. 400/1 Hall effect, a change in the distribution of current in a strip of metal, due to a magnetic field. 1958Van Nostrand's Sci. Encycl. (ed. 3) 784/1 In 1879 Hall..discovered that if a strip of gold-leaf, carrying an electric current longitudinally was placed in a magnetic field with the plane of the strip perpendicular to the direction of the field, points directly opposite each other on the edges of the strip acquired a difference of electric potential... The transverse electric potential gradient per unit magnetic field intensity per unit current density is called the ‘Hall coefficient’ for the metal in question... The Hall angle is the ratio of Ey..to the field Ex... The Hall mobility is the mobility of the electrons or holes in a semiconductor as measured by the Hall effect. 1965Phillips & Williams Inorg. Chem. I. vi. 195 Other methods which measure the mobility of the electrons, e.g. measurement of the Hall effect, also permit a distinction to be made between the two mechanisms of electron migration. |