When light enters from vacuum in to glass, its velocity?

Review the verified answer and explanation for this SPSC – Sindh Public Service Commission past-paper question on CampusFin.

When light enters from vacuum in to glass, its velocity? Answer: Decreases

When light passes from a vacuum (or air) into a denser medium like glass, its velocity decreases. This is because glass has a higher refractive index than vacuum, which slows the light down. However, the frequency remains constant, and the wavelength decreases.

Question context

This question is part of 🔬 General Science within the broader 🌐 Current Affairs & GK subject and appears in the SPSC – Sindh Public Service Commission preparation collection. Reviewing the answer together with nearby questions helps reinforce the underlying concept and identify how it may appear in competitive exams.