Question

    Which lens is used in sodium reflector lamp

    A Concave Correct Answer Incorrect Answer
    B Binocular Correct Answer Incorrect Answer
    C Convex Correct Answer Incorrect Answer
    D None of these Correct Answer Incorrect Answer

    Solution

    Convex mirrors are used as reflectors in sodium reflector lamps because they are able to spread the light over a wide area.  The neon gas  lights at a lower temperature. As the temperature increases the  sodium begins to vaporize and the  lamp turns to a pure yellow. Argon has a lower glow voltage, argon helps the smaller  lamps start at a lower voltage. The larger LPS lamps used in street  lighting for the most part do not use argon. 

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