Light Chapter Numericals aren’t just about calculation—they’re your scoring weapon in CBSE Term Exams. To help Class 10 students tackle this chapter with full clarity and confidence, we’ve compiled a set of “Must-Solve” numericals, strictly aligned with CBSE question patterns, board weightage, and past trends.
These questions are ideal for:
- ✅ Daily concept practice
- ✅ Exam revision drills
- ✅ Internal tests & sample paper preparation
- ✅ Confidence boosting before final boards
Important Numerical Topics Covered
Top 20 Most Important-Solve Light Chapter Numericals
Organized in two clear tables: Table 1 contains all 20 numericals, and Table 2 offers detailed step-by-step solutions, following CBSE sign convention and formula approach.
📑 Table 1: 20 Most Important Numerical Questions
| 🔢 Q.No | 📝 Numerical Problem |
|---|---|
| 1 | Object at 20 cm from concave mirror (f = 10 cm). Find image distance. |
| 2 | Convex mirror, object at 25 cm, focal length +15 cm. Find image distance. |
| 3 | Concave mirror forms image at 30 cm, object at 60 cm. Find focal length. |
| 4 | Object at 10 cm, image at 30 cm. Calculate magnification. |
| 5 | Convex lens: object at 20 cm, image at 40 cm. Find focal length. |
| 6 | Power of lens with focal length +25 cm. |
| 7 | Concave lens: object at 30 cm, image at 15 cm. Find focal length. |
| 8 | Object and image both at 60 cm in mirror. Find focal length and type. |
| 9 | Object at 25 cm from concave mirror (f = 10 cm). Find image distance and magnification. |
| 10 | Lens forms 5 cm image of 2 cm object. Object distance = 20 cm. Find image distance. |
| 11 | Concave mirror forms image at –40 cm, object at –30 cm. Find focal length. |
| 12 | Object at 60 cm from mirror, image formed at 20 cm. Find focal length. |
| 13 | Focal length –12 cm, image formed at –24 cm. Find object distance. |
| 14 | Lens with focal length –20 cm, object distance –40 cm. Find image distance. |
| 15 | Object at 10 cm from mirror (f = –5 cm). Find image position. |
| 16 | Image at –10 cm, focal length –5 cm. Find object distance. |
| 17 | Convex mirror: f = +15 cm, image distance +5 cm. Find object distance. |
| 18 | f = –25 cm, v = –25 cm. Find object distance. |
| 19 | v = –20 cm, u = –10 cm. Find focal length. |
| 20 | Convex mirror: object at –40 cm, image at +10 cm. Find focal length. |
✅ Table 2: Detailed Solutions
| 🔢 Q.No | 🧮 Solution |
|---|---|
| 1 | f = –10 cm, u = –20 cm → v = –20 cm |
| 2 | f = +15 cm, u = –25 cm → v ≈ +6.67 cm |
| 3 | u = –60 cm, v = –30 cm → f = –20 cm |
| 4 | u = –10, v = –30 → m = +3 |
| 5 | u = –20, v = +40 → f = +13.33 cm |
| 6 | f = 25 cm = 0.25 m → Power = +4D |
| 7 | u = –30, v = –15 → f = –30 cm |
| 8 | u = –60, v = –60 → f = –30 cm → Mirror = Concave |
| 9 | u = –25, f = –10 → v = –16.67 cm → m = +0.67 |
| 10 | h₀ = 2 cm, hᵢ = 5 cm → m = 2.5 → u = –20 → v = –50 cm |
| 11 | v = –40, u = –30 → f = –17.14 cm |
| 12 | v = –20, u = –60 → f = –15 cm |
| 13 | f = –12, v = –24 → u = –24 cm |
| 14 | f = –20, u = –40 → v = –40 cm |
| 15 | f = –5, u = –10 → v = –10 cm |
| 16 | f = –5, v = –10 → u = –10 cm |
| 17 | f = +15, v = +5 → u = –7.5 cm |
| 18 | f = –25, v = –25 → u = ∞ |
| 19 | v = –20, u = –10 → f = –6.67 cm |
| 20 | u = –40, v = +10 → f = +13.33 cm |
