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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 exam-ready
Assertion (A): The emergent ray from a rectangular glass slab is parallel to the incident ray but displaced laterally. Reason (R): At both parallel surfaces of the slab, refraction occurs such that the bending at the first surface is exactly reversed at the second surface, resulting in zero net angular deviation.
  1. A Both A and R are true, and R is the correct explanation of A.
  2. B Both A and R are true, but R is NOT the correct explanation of A.
  3. C A is true but R is false.
  4. D A is false but R is true.
Generated by claude-sonnet-4-6 · 2026-06-26 01:12 · grounding rag
Model Answer

Answer: A

Both A and R are true, and R is the correct explanation of A. The bending at the air-glass surface (AB) is exactly reversed at the glass-air surface (CD), giving zero net angular deviation but a lateral displacement.

Source: Chapter 9, Section 9.3.1

Explanation

The textbook explicitly states: "The extent of bending of the ray of light at the opposite parallel faces AB and CD is equal and opposite. This is why the ray emerges parallel to the incident ray." This directly confirms both the assertion (parallel but laterally displaced emergent ray) and the reason (equal and opposite bending at the two surfaces = zero net angular deviation). Since R correctly and completely explains A, option A is correct.

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