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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] straightforward exam-ready
According to the New Cartesian Sign Convention for spherical mirrors, an object is placed at a distance of 15 cm in front of a mirror. Which of the following correctly represents the object distance u? (A) u = +15 cm, measured to the right of the pole (B) u = –15 cm, measured to the left of the pole (C) u = +15 cm, measured from the principal focus (D) u = –15 cm, measured to the right of the pole
  1. A All distances are measured from the principal focus.
  2. B Distances measured to the right of the pole are negative.
  3. C Distances measured to the left of the pole are negative.
  4. D The object is always placed to the right of the mirror.
Generated by claude-sonnet-4-6 · 2026-06-26 01:11 · grounding rag
Model Answer

(B) u = –15 cm, measured to the left of the pole.

According to New Cartesian Sign Convention, distances measured to the left of the pole are negative; since the object is placed in front of (to the left of) the mirror, u = –15 cm.

Explanation

The key rule: all distances are measured from the pole, and leftward distances are negative. The object is always placed to the left of the mirror, so object distance u is always negative. Options A, C, and D are incorrect — distances are not measured from the focus, and leftward is negative (not positive). The correct MCQ answer is (B); the correct option statement is (C) — "Distances measured to the left of the pole are negative."

Source: Chapter 9, Section 9.2.3 Sign Convention for Reflection by Spherical Mirrors

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