# Numerical Aperture and Resolving power Objective Question

## Important Question

1. An objective capable of utilizing a large angular cone of light coming from the specimen will have:

• a) Equal resolving power to that of an objective utilizing smaller angular cone of light
• b) Better resolving power than an eye-piece utilizing smaller angular cone of light
• c) Better resolving power than an objective utilizing smaller angular cone of light
• d) None of the above

2. Which of the following is function of the objective lens?

• To gather the light in a point of an image
• To magnify the image
• To gather the light rays coming from any point of the object
• d) All of the above

3. Which of the following is the example of the type of objective?

• a) Achromatic
• b) Semi-apochromatic
• c) Apochromatic
• d) All of the above

4. Fluorite lens is also known as __ type of lens.

• a) Achromatic
• b) Semi-apochromatic
• c) Apochromatic
• d) None of the above

5. Which of the following lens is simplest in construction and cheapest one?

• a) Achromatic
• b) Fluorite
• c) Apochromatic
• d) None of the above

6. Which of the following lens is complex in construction and most expensive?

• a) Fluorite
• b) Achromatic
• c) Apochromatic
• d) Semi-apochromatic

7. Control of aberrations becomes:

• a) More difficult as the power increased
• b) Easier as the power increased
• c) Both of the above
• d) None of the above

8. Which of the following lens type possess least aberrations?

• a) Semi-apochromatic
• b) Apochromatic
• c) Achromatic
• d) All of the above

9. Which one of the following is exact definition of resolution?

• a) The ability of a lens to separate or distinguish between small objects those are far from each other
• b) The ability of a lens to separate or distinguish between small objects those are close together
• c) The ability of a lens to separate or distinguish between small objects that are overlapping each other
• d) None of the above

10. The measure of the resolving power of objective an objective is:

• a) Wavelength
• b) Resolution
• c) Numerical aperture
• d) Working distance

11. The _ the numerical aperture, the the resolving power of an objective:

• a) Larger, greater
• b) Smaller, greater
• c) Greater, smaller
• d) None of the above

12. In bright-field microscopy, to see minute objects it is advisable to use rays of:

• a) Larger wavelength
• b) Shorter wavelength
• c) Any wavelength as it does not matter
• d) Ultraviolet rays

13. The minimum distance between the images of two distinct objects as the angle of light coming from the object _:

• a) Decreases, increases
• b) Decreases, decreases
• c) Increases, increases
• d) Both b) and c)

14. The angle formed by the extreme rays is known as the _ of the objective.

• a) Aperture
• b) Resolution
• c) Working distance
• d) None of the above

15. The ability of objective lens system to form distinct images of two separate object points is proportional to what?

• a) Sine of the any angle
• b) Trigonometric sine of the angle
• c) Right angle
• d) All of the above

16. How will you define sine of an angle?

• a) It is the ratio of side adjacent to the angle in the acute angled triangle/hypotenuse
• b) It is the ratio of side opposite to the angle in the acute angled triangle/adjacent side to the angle
• c) It is the ratio of side adjacent to the angle in the right-angled triangle/hypotenuse
• d) It is the ratio of side opposite to the angle in the right-angled triangle/hypotenuse

17. Which of the following is the factor affecting resolving power of an objective?

• a) Angle of cone of light
• b) Refractive index of the space present in front of the lens
• c) Both of the above
• d) None of the above

18. The resolving power of the objective is directly proportional:

• a) To the width of the pencil of light used for illumination
• b) To the wavelength of light used for illumination
• c) Both of the above
• d) None of the above

19. The _ the pencil of light, the __ the resolving power.

• a) Wider, greater
• b) Narrower, greater
• c) Wider, smaller
• d) Narrower, smaller

20. If the wavelength of light used is 530 nm, numerical aperture is 1, what will be the minimal
distance between two objects that are nearby in the specimen?

• a) 5300 nm
• b) 265 nm
• c) 530 nm
• d) 2650 nm

21. If the wavelength of light used is 530 nm, numerical aperture is 2, what will be the minimal
distance between two objects that are nearby in the specimen?

• a) 5300 nm
• b) 265 nm
• c) 530 nm
• d) 2650 nm

22. The the wavelength of light, the the detail revealed by objective.

• a) Longer, finer
• b) Shorter, finer
• c) Longer, poorer
• d) Shorter, poorer

23. Which of the following filter will give you maximum resolving power?

• a) Yellow
• b) Green
• c) Violet
• d) None of the above

24. Which of the following light will give you maximum resolving power?

• a) Violet
• b) Green
• c) Ultra violet
• d) Yellow

25. Which of the following light will give you minimum resolving power?

• a) Violet
• b) Green
• c) Ultra violet
• d) Yellow

26. The mathematical equation for resolution was given by:

• a) Zacharias Janssen
• b) Antony van Leeuwenhoek
• c) Ernst Abbe
• d) Louis Pasteur

27. Minimum distance between 2 objects in specimen that reveals them as separate entities
depends on:

• a) Wavelength of light
• b) Numerical aperture
• c) Resolution
• d) Both a & b

28. What is numerical aperture?

• a) The ability of the lens to gather light
• b) The ability of the lens to scatter light
• c) Distance between 2 closer objects
• d) Diameter of any lens

29. By which formula numerical aperture is represented?

• a) ɳcosɵ
• b) ɳsinɵ
• c) dcosɵ
• d) ƛsinɵ

30. Minimal distance “d” between 2 objects in a specimen becomes smaller when:

• a) Light wavelength &numerical aperture increases
• b) Light wavelength &numerical aperture decreases
• c) Light wavelength increases &numerical aperture decreases
• d) Light wavelength decreases &numerical aperture increases