Physics XI Karachi Board Fill in the Blanks - Chapter 10

Chapter 10 - Geometrical Optics
1. A lens is a piece of __________ material that can focus a transmitted beam of light.

2. A lens is a piece of transparent material that can focus a __________ beam of light.

3. A lens is usually bounded by two __________ surfaces.

4. Lenses fall into __________ categories.

5. A convex lens is thicker in the middle and __________ on the edges.

6. A convex lens is __________ in the middle and thinner on the edges.

7. A convex lens __________ the light rays towards its optical axis.

8. A convex lens converges the light rays towards its __________.

9. A convex lens is thinner in the middle and __________ on the edges.

10. A diverging lens is __________ in the middle and thicker on the edges.

11. A concave lens __________ the light rays from its optical axis.

12. A diverging lens bends light rays from its __________.

13. The point to which the light rays are brought to focus is called __________.

14. The point to which the light rays are brought to __________ is called principal focus.

15. The distance between the optical centre of the lens and its principle focus is called __________.

16. The distance between the __________ of the lens and its principle focus is called its focal length.

17. The point is the lens through which the light rays will pass without any deviation is called its __________.

18. The point is the lens through which the light rays will pass without any deviation is called its __________.

19. In Convex lens, when the object is placed in between F and 2F then its image will form __________ on the other side of the lens.

20. Conventionally the focal length of the diverging lens is taken as __________.

21. When the two lenses are combined to form a single lens, then this lens is called __________ lens.

22. The defect in the lens is due to the fact that the focal points of the light rays far from the optical axis of a spherical lens are different from those rays passing through the centre is called __________.

23. Chromatic aberration can be reduced to a greater extent by the combination of __________ lenses.

24. The angle subtended by the object at the eye is called __________.

25. The least distance up to which a normal person could see the object without taking any strain on his eyes is called least distance of __________.

26. Compound microscope is an optical device, which is used to see the __________ object with very high magnification.

27. In compound microscope an eyepiece of __________ focal length is used.

28. In compound microscope to obtain the large magnification lenses of __________ focal length are used.

29. In compound microscope the eyepieces will be used as a __________.

30. Telescope is used to see __________ object.

31. The focal length of the objective in astronomical telescope is __________ than the focal length of eyepiece.

32. Galilean telescope is used to see the object on __________.

33. In Galilean telescope the convex lens will be used as an __________.

34. Terrestrial telescope consists of __________ lenses.

35. In spectromter, collimeter produces a __________ beam of light.

36. The spectrum of light in which the images overlap each other is called __________ spectrum.

37. The front of eye is covered by a transparent membrane called __________.

38. The abnormality in which the image of the distant object is focused in from of retina is called __________.

39. In the case of the abnormality named as Myopia the person is said to __________.

40. Short Sightedness can be corrected by using a __________ a lens.