Microscopy (Objective 3)

Question 1

Should oil be cleaned from the 100× objective using kleenex?

Answer 1

No

Question 2

True or false

Working distance increases as numerical aperture and magnification increases?

Answer 2

False

Question 3

True or False

If a specimen can be focused on 10x but is not in focus when switched to oil immersion objectives, the problem may be due to an upside down slide

Answer 3

True

Question 4

True or False

To adjust the oculars for the distance between your eyes,use the diopter adjustment on one of the oculars

Answer 4

False

Question 5

In what position should the swing out lens be in when using high power or oil immersion objectives?

Answer 5

In the light path

Question 6

The point where all light rays meet at a specific point after passing through a lens is referred to as?

Answer 6

Focal point

Question 7

How would you correct for spherical aberration?

Answer 7

Combining a strong convex and concave lens and blocking any light rays falling on the margerins of the lens

Question 8

Which microscope system is responsible for the real,inverted image?

Answer 8

Objective lens system

Question 9

On the oculars, the K engraving refers to what?

Answer 9

Compensating eye pieces

Question 10

True or False

Certain objectives are only designed for specific mechanical tube lengths?

Answer 10

True

Question 11

Which of the following is not a common magnification for an objective lens? 10x, 20x, 50x, or 100x

Answer 11

20x

Question 12

What magnification is considered a low power lens?

Answer 12

10x

Question 13

A black ring on the end of an objective or the markings “oi” refers to what?

Answer 13

The objective lens requires oil immersion.

Question 14

Well, focusing on a specimen initially on low power, you would use the course knob focus first until you see the specimen followed by the use of the fine focus knob until you obtain a clear sharp image.

True or false.

Answer 14

True

Question 15

True or false once you have focused on low power. When you switch to high power objectives, you should adjust the focus using the course focus mainly.

Answer 15

False

Question 16

Excess oil should be removed from the oil objectives using lens paper followed by lens, cleaner.

True or false?

Answer 16

True

Question 17

What lens system is closest to your eyes and provides a further 10x magnification?

Answer 17

Ocular lens system

Question 18

What magnification level lenses require oil immersion?

Answer 18

50x and 100x

Question 19

What happens to the working distance (WD) when you increase magnification?

Answer 19

It decreases

Question 20

If lens A has a numerical aperture of 1.25 and lens B has a numerical aperture of 0.25, what lens would give us better detail?

Answer 20

Lens A

Question 21

True or false. We use oil to increase the amount of light that enters the objective?

Answer 21

True

Question 22

What do we mean by the term parcentral when referring to microscopy?

Answer 22

The object remains centered when switching between objectives.

Question 23

Which part of the microscope should be adjusted to match the numerical aperture on the objective of lens?

Answer 23

The iris diaphragm.

Question 24

What is the general flow of light through a bright field microscope?

Answer 24

Light bulb, condenser unit, specimen, objectives, body tube, oculars.

Question 25

What is the total magnification of a specimen that is being viewed under a 40x objective?

Answer 25

400x

Question 26

True or false you can increase your resolving power by using a blue filter?

Answer 26

True

Question 27

The shortest distance between two points that can be distinguished as separate entities is referred to as?

Answer 27

Resolution

Question 28

What is the main purpose of kohler illumination?

Answer 28

To center and focus the light on the specimen to ensure optimal use of illumination.

Question 29

When you can focus on 10x but when moving to a higher power objective ( 50x or 100x) times you notice it is impossible to focus. What would you check first?

Answer 29

Check to see if the slide may be upside down.

Question 30

When setting kholer, you notice that the field of view is not centered when the field diaphragm is closed. What part of the microscope would be used to fix this?

Answer 30

Centering screws

Question 31

True or False Both the oculars and the objectives provide magnification of the specimen.

Answer 31

True

Question 32

What is the main purpose of the condenser lens system?

Answer 32

To focus the light rays onto the specimen by producing a cone of light that evenly illuminates the field.

Question 33

What is reflection?

Answer 33

Reflection is the returning of light from a surface ("bounce back")

Question 34

What is refraction?

Answer 34

Refraction is the bending of light as it passes from one transparent media to another of a different density.

Question 35

What happens to the speed of light when it travels from a less dense medium to a more dense medium?

Answer 35

Slows down

Question 36

What happens to the speed of light when it moves from a more dense medium to a less dense medium?

Answer 36

It's speeds up

Question 37

What is the formula for the refractive index?

Answer 37

N= speed of light in a vacuum ‐-------------------------- Speed of light in a given material

Question 38

What is the R.I. of Air?

Answer 38

1.00

Question 39

What is the R.I. of water?

Answer 39

1.33

Question 40

What is the R.I. of glass?

Answer 40

1.52 (1.46~1.92)

Question 41

What is the R.I. for immersion oil?

Answer 41

1.52

Question 42

What way will the light bend if the second medium is more dense? (Towards or away from the perpendicular)

Answer 42

Towards the perpendicular.

Question 43

What way will light bend if the second medium is less dense? (Towards or away from the perpendicular)

Answer 43

Away from the perpendicular.

Question 44

What is dispersion?

Answer 44

It is the separation of white light into colored components when light strikes a prism.

Question 45

In dispersion, what color of light is bent the most?

Answer 45

Violet

Question 46

In dispersion, what color of light is bent the least?

Answer 46

Red

Question 47

What is defraction?

Answer 47

It is the spreading out of light rays after encountering an opening.

Question 48

Is a convex lens positive or negative?

Answer 48

Positive.

Question 49

Is a concave lens positive or negative?

Answer 49

Negative.

Question 50

What is the focal point?

Answer 50

The focal point is the spot where the rays of light parallel to the principal access are brought together.

Question 51

What is focal length?

Answer 51

The focal length is the distance between the lens (optical center) and the focal point.

Question 52

The inability to focus all color components of light at the same focal point is known as?

Answer 52

Chromatic aberration

Question 53

Chromatic aberration is caused by what type of lens?

Answer 53

A convex lens causes dispersion into its components, which cause color to be formed at different focal points.

Question 54

What corrects chromatic aberration?

Answer 54

Combining convex and concave lenses. Can be further corrected by adding flourite element to the lens.

Question 55

Achromatic

Answer 55

2 color correction

Question 56

Apochromatic

Answer 56

3 color correction

Question 57

What is spherical aberration?

Answer 57

Curvature of a field, it results in a curved image of a flat object

Question 58

How can you correct spherical aberration?

Answer 58

By blocking light rays from falling on the marginal areas of the lens or by combining a strong positive lens with a negative lens, - the same that is done for chromatic aberration.

Question 59

Ocular lens system

Answer 59

Producers the final enlarged virtual image seen by our eyes

Question 60

Objective lens system

Answer 60

Produces the initial enlarged real inverted image of the object

Question 61

Condenser system

Answer 61

located below the object, it concentrates the light rays on the object

Question 62

Illumination system

Answer 62

The light source

Question 63

Mechanical support system

Answer 63

Arm and base of microscope. devices used for focusing and moving the object or a lens system.

Question 64

Engravings found on the ocular lens system

Answer 64

K or comp - Compensating eye piece, high quality, several lenses, flat field. Glasses symbol - High point lens for people with glasses. W - Wide field lens provides a large flat field of view. PL, F or EF - Flat field optical correction eye pieces. Periplan - Flat field also compensates for astigmatism and chromatic aberration.

Question 65

What happens to working distance with increased magnification?

Answer 65

Decreases

Question 66

What must be changed when you change the objective?

Answer 66

The iris diaphragm NA must match the objectives NA.

Question 67

What does a black ring on an objective mean?

Answer 67

Oil immersion

Question 68

What is the purpose of using oil?

Answer 68

Less light is refracted away from the lens, and more light will enter the objective. It increases the resolving power.

Question 69

Parfocal

Answer 69

Stays in focus when switching between objectives

Question 70

Parcentral

Answer 70

Object that's centered will remain centered when switching between objectives

Question 71

What does the condenser lens system do?

Answer 71

It focuses the light rays onto the specimen, producing a cone of light that illuminates the field evenly.

Question 72

The condenser lens system is also sometimes called?

Answer 72

Sub-stage condenser

Question 73

Mixing immersion oil types together may result in blurring True or false?

Answer 73

True

Question 74

In which type of microscope are specimens capable of bending light to appear as bright objects on a black field.?

Answer 74

Darkfield

Question 75

What type of microscope has the following set up: 2 filters, one placed on top of the field diagram and the other between your eyes and the ocular, allowing visualization of components that are birefringent..

Answer 75

Polarizing.

Question 76

What type of microscope uses the following principle: Specimen is illuminated using a specific short wavelength of light that is absorbed, and a longer wavelength is emitted to allow use to visualize.

Answer 76

Fluorescents

Question 77

What type of microscope is very expensive and provides the highest magnification of any other microscope?

Answer 77

Electron

Question 78

What type of microscope has the objectives and the oculars located below the stage?

Answer 78

Inverted microscope