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State PCS PYQPrelims 2021

UPPCS · प्रश्न 126

Which of the following types of glass can cut off ultraviolet rays?

  1. Soda glass
  2. Pyrex glass
  3. Jena glass
  4. Crookes glass
उत्तर देखें और व्याख्या

उत्तर: (D) Crookes glass

व्याख्या

Crookes glass contains cerium oxide, which absorbs UV; it is used in sunglasses.