the branch of physics concerned with electromagnetic phenomena
magnetism produced by an electric current; "electromagnetism was discovered when it was observed that a copper wire carrying an electric current can magnetize pieces of iron or steel near it"
the lagging of an effect behind its cause; especially the phenomenon in which the magnetic induction of a ferromagnetic material lags behind the changing magnetic field
having an indicated pole (as the distinction between positive and negative electric charges); "he got the polarity of the battery reversed"; "charges of opposite sign"
a variable quantity that can be resolved into components
any agent (person or animal or microorganism) that carries and transmits a disease; "mosquitos are vectors of malaria and yellow fever"; "fleas are vectors of the plague"; "aphids are transmitters of plant diseases"; "when medical scientists talk about vectors they are usually talking about insects"
a straight line segment whose length is magnitude and whose orientation in space is direction
memory device consisting of a long thin plastic strip coated with iron oxide; used to record audio or video signals or to store computer information; "he took along a dozen tapes to record the interview"
a part of the cell containing DNA and RNA and responsible for growth and reproduction
any histologically identifiable mass of neural cell bodies in the brain or spinal cord
the positively charged dense center of an atom
(astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail
any of various rotating shafts that serve as axes for larger rotating parts
(biology) tiny fibers that are seen in cell division; the fibers radiate from two poles and meet at the equator in the middle; "chromosomes are distributed by spindles in mitosis and meiosis"
marked by qualities giving the power to produce an intended effect; "written propaganda is less efficacious than the habits and prejudices...of the readers"-Aldous Huxley; "the medicine is efficacious in stopping a cough"