Top 25 questions of Light class 10 science

Top 25 questions of Light class 10 science (part 1)

1. Explain why a ray of light passing through the centre of curvature of a concave mirror gets reflected along the same path.  (Delhi 2010)
2. What is the nature of the image formed by a concave mirror if the magnification produced by the mirror is + 3?   (Delhi 2010)
3. Between which two points of a concave mirror should an object be placed to obtain a magnification of-3? (Delhi 2010)
4. The outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror. What will be the focal length of this mirror ? Which type of spherical mirror will it provide?
5. An object is kept at a distance of 4 m in front of a spherical mirror which forms its erect image at a distance of 1.0 m from the mirror. What is the magnification? Is the mirror concave or convex? (Foreign  2010)
6. A ray of light enters a rectangular glass slab of refractive index 1.5. It found that the ray emerges from the opposite face of the slab without being displaced. If its speed in air is 3 x 10⁸ ms-1 than what is its speed in glass?  Foreign 2010)
7. The speed of light in a transparent medium is 0.6 times that of its speed in vacuum. What is the refractive index of the medium? (Foreign 2010)
8. Why does a ray of light bend when it travels from one medium into another?  (Delhi 2009)
9. Light enters from air into glass having refractive index 1.50. The speed of light in vacuum is 3.0 x 10, 8 ms-1. What will its speed in glass be?  (Delhi 2008C)
10. A concave mirror is placed in water. Will there be any change in focal length? Give reason. (Delhi  2000C)
11. Is light a E.M. wave?
12. What is a real image? Give two uses of a concave mirror.
13. Name the type of mirror which always forms a virtual image for a real object.
14. What is the power of a plane mirror?
15. What is the value of refractive index of air?
16. What is the S.I. unit of power of a lens?
17. What is the power of a lens of focal length 50 cm?
18. A concave mirror forms sharp image of a distant tree. What is the separation between the mirror and the screen called?
19. Write the lens formula.
20. Define the angle of incidence.
21. Where will the image be if the object is at focus of the concave mirror?
22. Locate the position of image formed by a concave mirror if the object is at 2For C.
23. In which direction, the ray of light bends as it travels from denser to rarer medium?
24. The refractive index of water is 4/3 and for glass it is 3/2, with respect to air . What is the refractive index of glass with respect to water?
25. Where should an object be placed, so that a real and inverted image of the same size is obtained by a convex lens?