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Hall effect

(Encyclopedia)Hall effect, experiment that shows the sign of the charge carriers in a conductor. In 1879 E. H. Hall discovered that when he placed a metal strip carrying a current in a magnetic field, a voltage dif...

sports

(Encyclopedia)sports, athletic games or tests of skill undertaken primarily for the diversion of those who take part or those who observe them. The range is great; usually, however, the term is restricted to any pl...

magnetic resonance

(Encyclopedia)magnetic resonance, in physics and chemistry, phenomenon produced by simultaneously applying a steady magnetic field and electromagnetic radiation (usually radio waves) to a sample of atoms and then a...

Robertson, Sir William Robert

(Encyclopedia)Robertson, Sir William Robert, 1860–1933, British field marshal. He enlisted in the army in 1877 and became an officer in 1888. He was in the intelligence department in India (1892–96) and served ...

induction, in electricity and magnetism

(Encyclopedia)induction, in electricity and magnetism, common name for three distinct phenomena. Electromagnetic induction is the production of an electromotive force (emf) in a conductor as a result of a changing ...

paleomagnetism

(Encyclopedia)paleomagnetism, study of the intensity and orientation of the earth's magnetic field as preserved in the magnetic orientation of certain minerals found in rocks formed throughout geologic time. Paleom...

anabolic steroid

(Encyclopedia)anabolic steroid ănˌdrōjĕnˈĭk [key], any of a group of synthetic derivatives of testosterone that promote muscle and bone growth. Used to treat uncontrolled weight loss in wasting diseases, anab...

Flodden

(Encyclopedia)Flodden, field, Northumberland, N England, just across the border from Coldstream, Scotland. It was the scene of the battle of Flodden Field (1513), in which the English under Thomas Howard, 2d duke o...

Aub, Max

(Encyclopedia)Aub, Max mäks oup [key], 1903–72, Spanish author, b. Paris. He was educated in Spain where he lived until 1942, when he emigrated to Mexico. His style combines realism with fantasy. He used the Spa...

electromagnet

(Encyclopedia)CE5 Electromagnet electromagnet, device in which magnetism is produced by an electric current. Any electric current produces a magnetic field, but the field near an ordinary straight conductor is ...