Menu
Home / General Knowledge / Physics :: Discussion

Discussion :: Physics

  1. Forged documents are detected by

    2. A.

     Ultraviolet rays
    B.

     Infra-red rays
    C.

     Beta rays
    D.

     Gamma rays

    View Answer

    Workspace

    View Answer

    Answer : Option A

    Explanation :

    Old postcards, books, signs, photos and other paper products made before the late 1930s rarely glow under a black light. Chemical bleaches and dyes used in modern papers will fluoresce under ultraviolet light. Knowing this helps to detect forged documents and distinguish reproductions in all types of ephemera.

Write your comments here:

Be The First To Comment