Reflection & Refraction Numerical MCQs
Reflection & Refraction Numerical MCQs
Class: 12 | Subject: Physics
Section: 6 – Optics
Topic: Reflection & Refraction Numericals
Based on: CBSE Board Examination Pattern
Section: 6 – Optics
Topic: Reflection & Refraction Numericals
Based on: CBSE Board Examination Pattern
Instructions: These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 12 Board Examination preparation.
1. A ray strikes a plane mirror at 30°. Angle of reflection is:
Answer: A
Angle of incidence = Angle of reflection = 30°.
Angle of incidence = Angle of reflection = 30°.
2. Radius of curvature = 40 cm. Focal length of mirror:
Answer: B
f = R/2 = 20 cm.
f = R/2 = 20 cm.
3. Refractive index of glass = 1.5. Speed of light in glass:
Answer: A
v = c/μ = 3×10⁸ / 1.5 = 2×10⁸ m/s.
v = c/μ = 3×10⁸ / 1.5 = 2×10⁸ m/s.
4. Object at 10 cm, focal length 5 cm (convex lens). Image distance:
Answer: A
Using lens formula → v = 10 cm.
Using lens formula → v = 10 cm.
5. Power of lens f = 50 cm:
Answer: A
P = 1/f = 1/0.5 = 2 D.
P = 1/f = 1/0.5 = 2 D.
6. Critical angle when μ = 1.5:
Answer: B
sin C = 1/1.5.
sin C = 1/1.5.
7. Plane mirror magnification:
Answer: B
Image same size.
Image same size.
8. Concave mirror f = 10 cm, object at 20 cm → image:
Answer: C
Object at 2f → image at 2f.
Object at 2f → image at 2f.
9. Refractive index air–water:
Answer: A
10. Lens formula:
Answer: A
Gaussian lens formula.
Gaussian lens formula.
11. Mirror formula:
Answer: A
12. μ = sin i / sin r law:
Answer: B
13. Image distance sign for real image:
Answer: A
14. Convex mirror focal length sign:
Answer: A
15. Concave lens power sign:
Answer: B
16. Optical density relates to:
Answer: A
17. Minimum deviation prism formula involves:
Answer: D
18. Lens magnification:
Answer: A
19. Mirror magnification:
Answer: A
20. TIR occurs when i >:
Answer: B
