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Science (086) — AI-generated practice question

AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.

Q1. [1] medium initial-understanding
A ray of light travels from air into glass (a denser medium) obliquely. Which direction does it bend at the air-glass boundary, and what happens to its direction when it exits back into air at the opposite face? (A) Bends towards the normal entering glass; bends towards the normal exiting into air (B) Bends towards the normal entering glass; bends away from the normal exiting into air (C) Bends away from the normal entering glass; bends towards the normal exiting into air (D) Bends away from the normal entering glass; bends away from the normal exiting into air
  1. A Bends towards the normal entering glass; bends towards the normal exiting into air
  2. B Bends towards the normal entering glass; bends away from the normal exiting into air
  3. C Bends away from the normal entering glass; bends towards the normal exiting into air
  4. D Bends away from the normal entering glass; bends away from the normal exiting into air
Generated by claude-sonnet-4-6 · 2026-06-26 01:10 · grounding rag
Model Answer

(B)

When light travels from air (rarer) to glass (denser), it slows down and bends towards the normal. When it exits from glass (denser) back into air (rarer), it speeds up and bends away from the normal.

Explanation

The key rule from the textbook: rarer → denser = bends towards normal; denser → rarer = bends away from normal. This is directly stated in Section 9.3.2 and demonstrated in Activity 9.10 (Section 9.3.1). Don't confuse the two transitions — entry and exit are opposites. Option B captures both correctly.

Source: Chapter 9, Sections 9.3.1 and 9.3.2

Previous-year CBSE Grade 10 board exam questions, organised by subject and chapter, each with a model answer — free to read and print.