Bright field microscope Objective Question

MUST READ BEFORE CONTENT

  • Bold option is answer of question.
  • Preparation for Various Entrance Exams
  • Support for college / university Exams
  • All Doubts Clarification

1. Why ordinary microscope is called bright field microscope?

  • a) It forms a brighter image against dark background
  • b) It forms a darker image against bright background
  • c) It forms a brighter image in bright background
  • d) It forms a darker image in dark background

2. Which one of the following is a part of bright field microscope?

  • a) Arm
  • b) Diaphragm
  • c) Light source
  • d) All of the above

3. What is the function of condenser?

  • a) To create illumination
  • b) To move stage
  • c) To focus a cone of light on slide
  • d) All of the above

4. The image should remain in focus when objective lenses are changed. This property of microscope is known as:

  • a) Magnification
  • b) Resolution
  • c) Parfocal
  • d) None of the above

5. The lens nearer to eye, when viewing in microscope is known as:

  • a) Nose piece
  • b) Ocular lens
  • c) Objective lens
  • d) Oil immersion lens

6. Minimal resolvable distance between two objects is equal to:

  • a) 0.5ƛ/ɳ sin ɵ
  • b) 0.5ƛ/ɳ cos ɵ
  • c) 0.05ƛ/ɳ sin ɵ
  • d) 0.05ƛ/ɳ cos ɵ

7. What is the approximate focal length for scanning objective?

  • a) 20mm
  • b) 40mm
  • c) 10mm
  • d) 4mm

8. What should be the working distance for high power objective?

  • a) 0.5-0.7mm
  • b) 0.7-0.9mm
  • c) 0.9-1.0 mm
  • d) 1.0-1.2 mm

9. The resolving power is limited by the __ of the illuminating beam.

  • a) Frequency
  • b) Velocity
  • c) Speed
  • d) Wavelength

10. What is the numerical aperture of low power objective?

  • a) 0.65
  • b) 0.25
  • c) 1.25
  • d) 0.10

11. To focus a specimen, it is best to start with which objective?

  • a) High power
  • b) Low power
  • c) Scanning
  • d) Oil immersion

12. For which of the following specimens would you use a dissecting scope?

  • a) Human skin cells
  • b) Insect mouth parts
  • c) Escherichia coli
  • d) Newspaper print.

13. Which objective provides the greatest field to view?

  • a) This depends on if the specimen is stained
  • b) Low power
  • c) High power
  • d) Oil immersion

14. Which one can act as a source of illumination for microscopes?

  • a) Ultraviolet light
  • b) Sunlight
  • c) Visible light
  • d) All of the above

15. Which equation represents resolution of an entire microscope?

  • a) d/NAobjective + NAcondenser
  • b) ƛ/NAobjective x NAcondenser
  • c) ƛ/NAobjective + NAcondenser
  • d) d/NAobjective x NAcondenser

16. What would be the resolving power of microscope with low power objective (NA 0.25) and 530 nm light wavelength?

  • a) 212nm
  • b) 1060nm
  • c) 2120nm
  • d) 4240nm

17. What would be the resolving power of microscope with high power objective (NA 0.65) and 550 nm light wavelength?

  • a) 212nm
  • b) 846nm
  • c) 423nm
  • d) 1692nm

18. Identify correct match of magnification, numerical aperture, focal length, working distance
criteria shown in below columns:

Column AColumn B
1. Oil immersion objective        i)          4X, 0.10, 40 mm, 20 mm
2. High power objective        ii)         1000X, 1.25, 2 mm, 0.1 mm
3. Low power objective        iii)        45X, 0.65, 4 mm, 0.7mm
4. Scanning objective        iv)        10X, 0.25, 16mm, 8 mm
  • a) 1 and ii), 2 and iv), 3 and i), 4 and iii)
  • b) 1 and ii), 2 and iii), 3 and iv), 4 and i)
  • c) 1 and iii), 2 and i), 3 and ii), 4 and iv)
  • d) 1 and iv), 2 and iii), 3 and ii), 4 and i)

19. What do you mean by binocular microscope?

  • a) Contains 2 eyepieces
  • b) Contains only 2 objectives
  • c) Contains at least 2 objectives
  • d) Contains 2 lenses in eyepiece

20. Which microscope can be used to view living microbes?

  • a) Bright field microscope
  • b) Fluorescence microscope
  • c) Phase contrast microscope
  • d) All of the above

21. One micrometer is equal to:

  • a) 10-6 meter
  • b) 10-3 meter
  • c) 10-9 meter
  • d) 10-10 meter

22. What does binocular microscope contain?

  • a) Two oculars
  • b) Two objectives
  • c) One objective & one eye piece
  • d) Two oil immersion lenses

23. Which one of the following is exact definition of parfocal?

  • a) The image would be focused by fine adjustment
  • b) The image would be focused by coarse adjustment
  • c) Image should remain in focus, when objectives are changed
  • d) Image should remain in focus, when oculars are changed

24. The image what we observe in microscope is created by:

  • a) Objective
  • b) Ocular
  • c) Both a & b
  • d) Either of a or b

25. How will you calculate total magnification of image?

  • a) By making total of magnification of objective &eyepiece
  • b) By making multiplication of magnification of objective &eyepiece
  • c) By total of magnification of all objectives attached to nose piece
  • d) By multiplication of magnification of all objectives attached to nose piece

26. If microscope contains 45x objective &5x eyepiece, the total magnification will be:

  • a) 450x
  • b) 225x
  • c) 125x
  • d) 50x

27. 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

28. To obtain greatest possible resolution in bright field microscope one can use light with
wavelength:

  • a) 450-500nm
  • b) 500-550nm
  • c) 550-600nm
  • d) 700-800nm

29. The refractive index of air is:

  • a) 0.1
  • b) 1
  • c) 10
  • d) None of the above

30. The refractive index of glass &cedar wood oil is:

  • a) About 1.1
  • b) Differ about 0.5 from each other
  • c) Nearer to each other
  • d) 10 times higher than air

31. The refractive index of glass & cedar wood oil is:

  • a) About 1.5 times higher than air
  • b) Nearer to each other
  • c) Average 1.53
  • d) All of the above

32. The lens working in an air cannot have numerical aperture more than:

  • a) 1.25
  • b) 1.00
  • c) 0.65
  • d) 0.25

33. How can we increase numerical aperture more than 1?

  • a) By using air
  • b) By using immersion oil
  • c) Both a & b
  • d) None of the above

34. Which of the following are true magnification, numerical aperture, focal length & working
distance of criteria for an oil immersion lens?

  • a) 45X, 0.65, 4mm, 0.7mm
  • b) 100X, 1.25, 1.8mm, 0.1mm
  • c) 100X, 0.25, 16mm, 8mm
  • d) 4X, 0.10, 40mm, 20mm

35. Which of the following are true magnification, numerical aperture, focal length & working
distance of criteria for high power objective?

  • a) 45X, 0.65, 4mm, 0.7mm
  • b) 100X, 1.25, 1.8mm, 0.3mm
  • c) 100X, 0.65, 16mm, 8mm
  • d) 4X, 0.10, 60mm, 20mm

36. Which of the following are true magnification, numerical aperture, focal length & working
distance of criteria for low power objective?

  • a) 45X, 0.25, 16mm, 0.7mm
  • b) 100X, 1.25, 3.8mm, 0.1mm
  • c) 10X, 0.25, 16mm, 8mm
  • d) 4X, 0.10, 40mm, 30mm

37. In ɳsinɵ equation of numerical aperture, ɵ is:

  • a) The angle of the cone of light entering in an objective
  • b) 1/2angle of the cone of light entering in an objective
  • c) 1/4 angle of the cone of light entering in an objective
  • d) None of the above

38. In ɳsinɵ equation maximum value of ɵ is:

  • a) 90°
  • b) 45°
  • c) 180°
  • d) 360°

39. The maximum value of sinɵ is:

  • a) 0.5
  • b) 0.65
  • c) 1.00
  • d) 1.25

40. The working distance can be defined as the distance between:

  • a) Objective &eyepiece
  • b) 2 objectives
  • c) Objective &condenser
  • d) Objective &specimen on slide

41. Which of the following objective works on shortest working distance?

  • a) Low power
  • b) Scanning lens
  • c) Oil immersion lens
  • d) High power

42. The objective with large working distance will have:

  • a) Small numerical aperture &low resolving power
  • b) Large numerical aperture &high resolving power
  • c) Large numerical aperture &low resolving power
  • d) Small numerical aperture &high resolving power

43. The resolution of microscope depends on:

  • a) Numerical aperture of objective
  • b) Numerical aperture of condenser
  • c) Wavelength of light
  • d) All of the above

44. Microscope condenser contains numerical aperture about:

  • a) 1.0
  • b) 1.3
  • c) 1.5
  • d) 2.0

45. The maximum obtainable theoretical resolution of light microscope with oil immersion lens is:

  • a) 212nm
  • b) 312nm
  • c) 112nm
  • d) 252nm

46. What is the maximum obtainable theoretical resolution of light microscope with oil immersion lens?

  • a) 0.2μm
  • b) 0.3μm
  • c) 0.02μm
  • d) 0.03μm

47. A light microscope can maximum distinguishes between 2 dots about __μm apart:

  • a) 0.3μm
  • b) 0.2μm
  • c) 0.1μm
  • d) 0.4μm

48. can prepare bright field microscope with even 10,000X magnification, but it is not useful
because:

  • a) It is costlier
  • b) It would simply magnify blur
  • c) Increase the amount of artifacts
  • d) All of the above

Leave a Comment