everyday science MCQ #5669

For making a laser, usually we use:

everyday science MCQ #5669

  1. Question 1

    Q1. For making a laser, usually we use:

    • A) Uranium
    • B) Ruby
    • C) Magnesium
    • D) Iron

    Answer: Ruby

    Explanation: The first lasers used synthetic ruby (chromium-doped aluminum oxide) crystals as the gain medium, producing a red laser beam at 694 nm wavelength.