## 07 November 2011

### Sample Paper X Physics Light Reflection and Refraction

1. What is radius of plane mirror?

2. What is angle of reflection for a ray falling normally on a plane mirror?

3. Why do we use convex surface for side view mirror?

4. Can a virtual image be photographed?

5. What is the power of a plane mirror?

6. When the angle of incidence is 90 deg., what is the angle of refraction?

7. What is the value of refractive index of air?

8. What is the magnification produced by a plane mirror?

9. Define power. Give its S.I unit?

10. What is power of sunglass?

11. A convex mirror produced sharp image of a distant tree. What is the separation between the mirror and

the  screen called?

12. What is the emergent angle of light after reflection in a glass slab?

13. Where the images in a concave mirror form if the object is at 2F?

14. A person wants to see the full length of a tall building in a small mirror . Which type of mirror should be used  by him?

15. Magnification produced by a concave mirror of a body 4cm in size is 0.16 . what is the size of image?

16. What is the speed of light in glass of refractive index 1.5 ? The speed of light in vacuum is 3 lakhs km/sec

17. Where should  an object be placed, so that a real and inverted image of same size is obtained by a convex lens?

18. As we came down to surface of earth from a distant star how does the refractive index will change?

19. The refractive index of water is 4/3 and that of glass is 3/2 with respect to air . What is refractive index
of  glass with respect to water?

20. If 2 lenses of power P1 and P2 are kept in contact, what will be the net power?

1. Why are we advised not to see sun directly?

2. Distinguish between concave and convex mirror.

3. What is refractive index?  Why does light bend on refraction.

4. What is the nature of image formed by a convex lens when object is between focus and optical centre?

Draw ray diagram.

5. An object placed 45cm from a lens forms an image on screen placed 90cm on the other side of lens. Identify the lens and its focal length.

6. What is lateral displacement? What are the factors that affect it?

1. An object 3 cm high is placed at 27cm from a convex mirror of radius of curvature 36cm. Find the position, nature and size of the image.

2. An object of size 3 cm is placed at a distance 27c m from pole of a concave mirror which produce a real image  6 cm high,
(a) What is focal length of the mirror?
(b) Find the position of the images.

3. A square wire of side 3 cm is placed 25 cm away from a concave mirror of focal length 10cm. What is the area enclosed by the image of the wire? The centre of the wire is on the axis of mirror with its two sides normal to the axis.

4. A small candle 2.5cm in size is placed at 27 cm in front of a concave mirror of radius of curvature 0.36 m. At what distance from the mirror should a screen be placed in order to receive a sharp image? Describe
the nature and size of image if the candle is moved closed to the mirror, how would the screen have to
be moved?

5. What are laws of refraction? How the ray of light will bends when it travel from,
(a) denser to rarer medium