CBSE Class 12 Physics Worksheet (7) - Practice worksheets for CBSE students. Prepared by teachers of the best CBSE schools in India.
1. Suppose x & y are distance of object and image respectively from a mirror. What shall be the shape of the graph between 1/x & 1/y for a concave mirror?
2. An object is seen first in red light and then in violet light through a simple microscope. In which case is the magnifying power of simple microscope greater?
3. A lens of glass is immersed in water. What will be its effect on the power of the lens?
4. A thin prism of 600 angle gives a deviation of 300. What is the refractive index of material of prism?= (Ans: = 1.5)
6. What is the function of cladding in a typical optical fiber?
7. State the conditions for total internal reflection of light to take place.
8. How can you increase the magnifying power of a telescope?
9. Why is the secondary rainbow always fainter than the primary rainbow?
10. If a g = 3/2 and a w = 4/3, then what will be the value of w g ?
11. What causes brilliance of diamond?
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12. Prove that virtual image produced by a convex mirror is always diminished in size & is located between the focus and the pole.
13. A glass slab is placed over a page in which letters are printed in different colours. Will image of all letters lie in the same plane?
14. Why does a parallel faced glass slab produce neither deviation nor dispersion?
15. Why do we prefer reflecting type telescope for astronomical purposes?
16. An object is placed in front of a convex mirror of focal length 60 cm. if image formed is half its size, find the position of image. = 30cm
17. A mark is made at the bottom of a beaker and a microscope is focused on it. The microscope is then raised through 0.015 m to what height water must be poured into beaker to bring the mark again into focus? Given a w = 4/3,
18. The radius of curvature of each surface of a convex lens of refractive index 1.5 is 0.40m calculate its power.
19. Derive the relation between refractive index of a medium and its critical angle.
20. Draw a ray diagram to show the formation of the image of an object placed between f and 2f of a thin concave lens. Deduce the relation between the object, image distance and focal length of the lens under this condition.
21. A ray of light is refracted through a prism in the position of minimum deviation. The angle of prism 600 and its refractive index 1.532. Calculate the angle of incidence & min deviation.
22. Show by ray diagrams how a totally reflecting glass prism can be used to deviate a ray of light through (i) 900 (ii) 1800
23. A converging lens has a focal length of 20cm in air. It is made of material of refractive index 1.6. if it is immersed in a liquid of refractive index 1.3, what will be its new focal length?
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