cross section

cross section


: a view or drawing that shows what the inside of something looks like after a cut has been made across it

: a small group that includes examples of the different types of people or things in a larger group

Full Definition of CROSS SECTION

a :  a cutting or piece of something cut off at right angles to an axis; also :  a representation of such a cutting
b :  section 3b
:  a measure of the probability of an encounter between particles such as will result in a specified effect (as scattering or capture)
:  a composite representation typifying the constituents of a thing in their relations
cross–section transitive verb
cross–sec·tion·al \ˈkrs-ˈsek-shnəl, -shə-nəl\ adjective


  1. a detailed cross section of the human brain
  2. The drawing showed the human brain in cross section.
  3. The class surveyed a cross section of the student body.
  4. The people in our neighborhood are a representative cross section of American society.

First Known Use of CROSS SECTION


cross section

noun    (Medical Dictionary)

Medical Definition of CROSS SECTION

: a cutting or piece of something cut off at right angles to an axis; also : a representation of such a cutting
cross–sec·tion·al \ˌkr(s)-ˈsek-shnəl, -shən-əl\ adjective

cross section

noun    (Concise Encyclopedia)

In nuclear physics, a measure of the probability that a given atomic nucleus will exhibit a specific reaction (absorption, scattering, or nuclear fission) in relation to a particular incident particle. Cross section is expressed in terms of area, and its value is chosen so that, if the bombarding particle hits a circular target of this size perpendicular to its path and centred at the nucleus, the given reaction occurs. If it misses the area, the reaction does not occur. The unit of cross section is the barn, which equals 1024 sq cm. Cross-section values for a given nucleus depend on the energy of the bombarding particle and the kind of reaction and are often different from the actual cross-sectional area of the nucleus.


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