Light — Numerical Practice

Grade 10 Science — Light — Numerical Practice: 25 practice questions with instant scoring and explanations.

1. A concave mirror has focal length 15 cm. An object is placed 30 cm from it. Using the mirror formula, where is the image formed?
2. A lens of focal length 10 cm is used to form image. If object distance is 15 cm, calculate image distance using 1/f = 1/u + 1/v.
3. Calculate magnification for a mirror when u = 20 cm and v = -40 cm using m = -v/u.
4. The power of a lens with focal length 0.5 m is:
5. A convex lens (f = 20 cm) forms image at v = 60 cm. What is the object distance?
6. Power of two lenses combined is: P = P₁ + P₂ if lenses are in contact. If P₁ = 2 D and P₂ = 3 D, total power is:
7. A concave mirror produces magnification m = -3. If object is at 10 cm, find image distance.
8. Focal length of a lens is -25 cm. Its power is:
9. Using mirror formula, if f = 10 cm and u = 20 cm, then v =:
10. Magnification of a lens is +2. If image is real, the object must be:
11. A convex mirror has f = 20 cm. For an object at 40 cm, image distance is:
12. Two lenses of power +5 D and -2 D are in contact. Net power is:
13. If magnification m = -0.5, then image is:
14. A lens of focal length 5 cm has power of:
15. Using lens formula, if f = 15 cm and u = 30 cm, find v.
16. Object is placed at 2f from a concave mirror. Image is formed at:
17. A concave lens always forms image that is:
18. Calculate magnification for lens with u = 20 cm, v = 40 cm.
19. A diverging lens has power -10 D. Its focal length is:
20. If object is placed beyond 2f from concave mirror, image is:
21. Focal length of a mirror is related to radius of curvature by: f = R/2. If R = 30 cm, f is:
22. Two lenses with powers 4 D and -1.5 D are placed together. Effective power is:
23. Object height is 2 cm, image height is -6 cm. Magnification is:
24. A convex lens of power 5 D forms an image. If u = 40 cm, find v using lens formula.
25. If magnification is positive and less than 1, image is: