1. State the colour of sunlight scattered by air molecules in the atmosphere.
2. List four characteristics of images formed by plane mirrors.
3. What is dispersion ? What happens when light is passed through a glass prism.
4. What is meant by near point and far point of an eye ? State their values for the normal human eye.
5. State the reason of using convex mirrors as rear-view mirrors. A convex mirror used on an automobile has a focal length of 3 m. If a car behind is at a distance of 5 m, find the location of image of the car in the mirror.
6. Define power of a lens and state its SI unit. Which type of lens has a negative power ? Find the power of a lens of focal length +20 cm.
7. A person cannot see nearby objects clearly. State the defect of vision he is suffering from. Draw ray diagrams to show the defect and correction. Name the lens used for correction.
8. A concave lens of focal length 20 cm forms an image 10 cm away from the lens. Use lens formula to find the position of the object with respect to the lens. Also draw ray diagram to illustrate the image formed in this case.
9. (a) State the laws of refraction of light.
(b) Using the lens formula and sign conventions for refraction by spherical lenses find the position nature and magnification of the image formed by a convex lens of focal length 20 cm when object is placed at a distance of 18 cm from the lens.
10. A person suffering from an eye-defect uses lenses of power - 1D .Name the defect he is suffering from and the nature of lens used.
11. What is minimum number of rays required for locating the image formed by a concave mirror for an object? Draw a ray diagram to show the formation of a virtual image by a concave mirror.
12. An old person is unable to see clearly nearby object as well as distant objects.
(i) What defect of vision is he suffering from?
(ii) What kind of lens will be required to see clearly the nearby as well as distant objects? Give reasons?
13.(a) What is dispersion of light ?
(b) Name the :
(i) component of white light that deviates the least,
(ii) component of white light that deviates the most, while passing through a glass prism.
14. (a) Two lenses have power of i) +2 D ii) -4D.
What is the nature and focal length of each lens
(b) An object is kept at a distance of 100cm for lens of power-4D. Calculate image distance.
15. (a) A concave mirror produces three times enlarged image of an object placed at 10cm. in front of it. Calculate the focal length of the mirror.
(b) Show the formation of the image with the help of a ray diagram when object is placed 6 cm away from the pole of a convex mirror.
16. (a) The refractive index of diamond is 2.42. What is the meaning of this statement?
(b) What is the difference between virtual images produced by concave, plane and convex mirrors ?
(c) What does the negative sign in the value of magnification produced by a mirror indicates about a image ?
17. (a) Write one use of concave mirror as well as convex mirror.
(b) Draw ray diagrams for the following cases when a ray of light :
(i) passing through centre of curvature of a concave mirror is incident on it.
(ii) parallel to principal axis is incident on convex mirror
(iii) is incident at the pole of a convex mirror
(iv) passing through focus of a concave mirror incident on it.
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