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| Q. |
Forged documents are detected by – |
| A. | ultraviolet rays |
| B. | infra-red rays |
| C. | beta rays |
| D. | gamma rays |
| Answer» A. ultraviolet rays | |
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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. |
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