Class 10 Science Chapter 9 | Light - Reflection and Refraction | Top 40 MCQ for Board Exam 2026

Prepare for your Class 10 Science Board Exam 2026 with this comprehensive revision of Chapter 9: Light - Reflection and Refraction (Prakash - Paravartan tatha Apvartan). In this live session, we cover the Top 40 Multiple Choice Questions (MCQs) that are crucial for your exams, focusing on the fundamental principles of light, mirrors, and lenses. We discuss key concepts including laws of reflection and refraction, mirror formula, lens formula, magnification, and power of lenses. Key Topics Covered: Nature of Light: Rectilinear propagation Reflection of Light: Laws of reflection, Plane mirrors (Virtual & Erect image) Spherical Mirrors: Concave and Convex mirrors Mirror Formula & Magnification Refraction of Light: Laws of refraction (Snell's Law), Refractive Index Spherical Lenses: Concave and Convex lenses Lens Formula, Magnification & Power of Lens Uses of Mirrors: Shaving mirrors, Rear-view mirrors, Headlights Atmospheric Refraction & Twinkling of stars (Brief mention in context) Formulas Discussed: Relationship between Radius of Curvature and Focal Length: R = 2f Mirror Formula: 1/v + 1/u = 1/f Lens Formula: 1/v - 1/u = 1/f Power of Lens: P = 1/f (in meters) Refractive Index: n = c/v Snell's Law: sin i / sin r = constant Make sure to watch the full video to clear your doubts and strengthen your physics concepts. Timestamps: 00:00:00 Introduction & Chapter Overview 00:02:13 Q1: How does light travel? (Straight Line) 00:03:55 Q2: How many laws of reflection are there? (Two) 00:06:40 Q3: Image formed by a plane mirror is always? (Virtual & Erect) 00:07:49 Q4: Relation between focal length (f) and radius of curvature (R) (R = 2f) 00:12:05 Q5: Which mirror is used for shaving? (Concave Mirror) 00:14:18 Q6: Which mirror is used as a rear-view mirror in vehicles? (Convex Mirror) 00:15:53 Q7: Which mirror always forms a virtual, erect, and diminished image? (Convex Mirror) 00:17:04 Q8: Where is the image formed if an object is at focus of a concave mirror? (At Infinity) 00:18:49 Q9: Sign of focal length for a convex mirror (Positive) 00:20:47 Q10: Mirror used by dentists to see larger image of teeth (Concave Mirror) 00:22:01 Q11: Speed of light in vacuum (3 × 10^8 m/s) 00:24:18 Q12: Mirror Formula (1/v + 1/u = 1/f) 00:27:09 Q13: Line joining the pole and center of curvature is called? (Principal Axis) 00:28:07 Q14: Numerical: Find focal length if radius of curvature is 32 cm (16 cm) 00:31:04 Q15: Which material cannot be used to make a lens? (Clay/Soil) 00:34:12 Q16: Cause of refraction of light (Change in speed of light) 00:45:47 Q17: When light goes from rarer to denser medium, it bends? (Towards the normal) 00:45:39 Q18: Snell's Law relates to? (Refraction) 00:48:29 Q19: Mathematical form of Snell's Law (sin i / sin r = constant) 00:50:21 Q20: Refractive Index of Diamond (2.42) 00:52:04 Q21: Why does a pencil partially immersed in water appear bent? (Refraction) 00:54:03 Q22: SI Unit of Power of Lens (Dioptre) 00:55:59 Q23: Numerical: Power of a convex lens with focal length 25 cm (+4 D) 00:57:55 Q24: Which lens is also called a converging lens? (Convex Lens) 01:01:27 Q25: Image formed by a concave lens is always? (Virtual, Erect, Diminished) 01:11:17 Q26: Lens Formula (1/v - 1/u = 1/f) 01:12:58 Q27: Nature of image if magnification (m) is negative (Real and Inverted) 01:14:37 Q28: Mirror used in solar furnaces (Concave Mirror) 01:17:02 Q29: Refractive index of a medium with respect to vacuum is called? (Absolute Refractive Index) 01:17:52 Q30: Numerical: Speed of light in glass if refractive index is 1.5 (2 × 10^8 m/s) 01:20:35 Q31: Which lens is used to read small letters in a dictionary? (Convex Lens with small focal length) 01:23:05 Q32: Diameter of the circular outline of a spherical mirror is called? (Aperture) 01:25:05 Q33: Where is the image formed if object is at 2F1 in a convex lens? (At 2F2) 01:25:53 Q34: Condition for virtual, erect and magnified image in concave mirror (Object between Pole and Focus) 01:27:53 Q35: Type of lens with power -2.0 D (Concave Lens) 01:28:44 Q36: Refractive Index of Water (1.33) 01:29:23 Q37: When light goes from denser to rarer medium, it bends? (Away from normal) 01:30:09 Q38: Position of object for real, same-sized image in convex lens (At 2F) 01:31:46 Q39: Sign convention for object distance (u) (Always Negative) 01:33:06 Q40: Use of concave mirrors in torches and headlights 01:35:29 Conclusion & Next Class Details #Class10Science #LightReflectionAndRefraction #PhysicsMCQ #BoardExam2026 #Class10Revision #PraveenJoshiClasses