Class 12 Physics — Chapter 9: Ray Optics and Optical Instruments
90 practice questions · 30 Easy · 30 Medium · 30 Hard
Practise Class 12 Physics Chapter 9, "Ray Optics and Optical Instruments", with 90 NCERT-aligned multiple-choice questions. The set is split into 30 Easy, 30 Medium and 30 Hard questions, so you can warm up on the fundamentals and then push into the exam-level problems that separate top scorers in CBSE Board exams, JEE Main, JEE Advanced and NEET UG.
"Ray Optics and Optical Instruments" is one of the chapters where numerical problem-solving, derivations and conceptual application really pays off. Each MCQ on this chapter is timed and uses exam-grade marking (+2 correct, −1 wrong, 0 skipped), training the same accuracy-under-pressure that real papers demand. Every question carries a short explanation, so a wrong answer becomes a quick lesson rather than a dead end — the fastest way to close gaps before a test.
Use this chapter as targeted revision: attempt the Easy set first to confirm your basics on Ray Optics and Optical Instruments, then move to Medium and Hard to test application and problem-solving. Your accuracy, streaks and XP save automatically, and the chapter feeds into your overall Class 12 Physics mastery score. A few sample questions are shown below; sign in free to practise all 90.
Key concepts: Ray Optics and Optical Instruments (Class 12 Physics)
This chapter covers reflection and refraction at spherical surfaces, the lens and mirror formulae, total internal reflection, prisms, and optical instruments.
- Reflection & mirrors
- Spherical mirrors obey the mirror formula 1/v + 1/u = 1/f, with magnification m = −v/u.
- Refraction & Snell's law
- n₁sinθ₁ = n₂sinθ₂; refractive index n = c/v relates speed of light to bending of rays.
- Total internal reflection
- Occurs when light goes from denser to rarer medium beyond the critical angle (sinC = 1/n); basis of optical fibres.
- Lens formula & power
- 1/v − 1/u = 1/f; lens power P = 1/f (in dioptres); the lens-maker's formula relates f to radii and n.
- Optical instruments
- Microscopes and telescopes use lens combinations; magnifying power depends on the focal lengths.
Key formulas — Ray Optics and Optical Instruments
💡 Exam tips for Ray Optics and Optical Instruments
- Follow the sign convention strictly (distances measured from the pole/optical centre, with sign).
- Critical angle: sinC = 1/n — total internal reflection needs denser-to-rarer and angle > C.
Sample questions
Power of a lens unit:
P = 1/f (in metres).
Lens formula:
Sign convention applies.
Compound microscope uses:
Both magnify; total M = M_o × M_e.
Ray Optics and Optical Instruments — FAQs
What are the key concepts in Class 12 Physics Ray Optics and Optical Instruments?+
This chapter covers reflection and refraction at spherical surfaces, the lens and mirror formulae, total internal reflection, prisms, and optical instruments. Key ideas include Reflection & mirrors, Refraction & Snell's law, Total internal reflection, Lens formula & power, Optical instruments.
What does Class 12 Physics Chapter 9 (Ray Optics and Optical Instruments) cover on XamBaaz?+
It covers 90 NCERT-aligned MCQs on "Ray Optics and Optical Instruments" — 30 Easy, 30 Medium and 30 Hard — each with a timed quiz and an instant explanation, suitable for CBSE Board exams, JEE Main, JEE Advanced and NEET UG.
Are these "Ray Optics and Optical Instruments" questions free to practise?+
Yes — sign in with Google to practise "Ray Optics and Optical Instruments" free. Full unlimited access is ₹999/year (limited-time launch price), with no per-chapter charges.
How should I revise "Ray Optics and Optical Instruments" for the exam?+
Start with the Easy quiz to confirm your fundamentals, then attempt Medium and Hard for application-level practice. Review each explanation, retry the questions you miss, and track your accuracy on this chapter until it is consistently high.
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