Light - Refraction

Grade 9 Science — Light - Refraction: 25 practice questions with instant scoring and explanations.

1. Refraction of light occurs when:
2. Snell's law is expressed as:
3. The refractive index of a medium is defined as:
4. The refractive index of glass is approximately:
5. When light travels from air to glass, it:
6. If light travels from water (n = 1.33) to air (n = 1.0) at an angle of incidence 30°, the refraction angle is:
7. Critical angle exists when light travels from:
8. Total internal reflection occurs when angle of incidence:
9. Optical fibre works on the principle of:
10. A glass slab immersed in water shifts an incident ray but does NOT deviate the ray completely. This is because:
11. A convex lens converges light rays at:
12. A concave lens diverges light as if coming from:
13. The lens formula is:
14. For a convex lens with f = 20 cm, if u = 40 cm, then image distance (v) is:
15. A concave lens always produces:
16. Power of a lens (P) is defined as:
17. A lens with power +5 D has focal length:
18. For a convex lens forming a real, magnified image, the object is placed:
19. A concave lens used as a diverging lens has:
20. If a convex lens forms an image of magnification -2, the object is:
21. The SI unit of power of a lens is:
22. A person suffering from myopia (short-sightedness) needs:
23. A person with hypermetropia (long-sightedness) requires:
24. Dispersion of light occurs because:
25. When white light passes through a prism, the colour that deviates the least is: