What does "intensity" mean?

Intensity: (Physics) The amount or degree of energy with which a force operates or a cause acts; effectiveness, as estimated by results produced.

Additional senses

  1. 2.(Mech.) The magnitude of a distributed force, as pressure, stress, weight, etc., per unit of surface, or of volume, as the case may be; as, the measure of the intensity of a total stress of forty pounds which is distributed uniformly over a surface of four square inches area is ten pounds per square inch.
  2. 3.(Photog.) The degree or depth of shade in a picture.

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