Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MEDL 210 > Module 2 > Flashcards

Module 2 Flashcards

1
Q

What is the focal point?

A

The point at which parallel light rays converge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is focal length?

A

The distance from the centre of the lens to the focal point (lens to focused light).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the focal plane?

A

The vertical plane the plane of focus lies in.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is working distance?

A

The distance from the specimen to the objective lens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does working distance relate to magnification?

A

The shorter it is the greater the magnification.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the depth of field?

A

The range in which the object is in focus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What lenses have a narrower range of focus?

A

Higher magnification lenses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the conjugate foci?

A

The object and its formed image.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does focal length change the formed image? (Eg. If it’s 2F what does it look like? Etc.)

A

> 2F- real, smaller, inverted

2F- real, same size, inverted

2F-1F- real, magnified, inverted

1F- rays emerge parallel (no image)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What two lenses does a compound microscope combine?

A

Objective and ocular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the working distances of the lenses in the compound microscope?

A

Objective: 1F-2F

Ocular:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the object the ocular lens of a compound microscope focuses on?

A

The real image created by the objective.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is total magnification determined?

A

Multiplying the magnification of the objective and ocular lenses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What causes aberrations?

A

Refraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the different kinds of aberrations and why do they form?

A

Chromatic- different wavelengths have different focal points so colours are distorted

Spherical- light in the centre doesn’t refract as much as the periphery which appears blurred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the lenses that correct for aberrations?

A

Achromatic- red and blue

Semiapochromats- red, blue and some green

Apochromats- red, blue and green

Plan- produce flat fields of view

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do plan- lenses correct?

A

Combinations of convex and concave lenses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the parts of the compound microscope?

A 
Light source (radiant field diaphragm)
Condenser assembly (aperture diaphragm and lens system)
Stage assembly
Nosepiece/objectives
Body tube
Oculars
19
Q

Objectives do not need to be reduced when increasing magnification because why?

A

They are parfocal.

20
Q

What is mechanical tube length?

A

Distance from the top of the ocular to the objective junction.

21
Q

What is optical tube length?

A

The distance from the objective lens and the focal plane of the ocular.

22
Q

What is the common range of viewing field size?

A

19-22mm

23
Q

What does the amount of refraction depend on?

A

Angle of incidence- angle at which light strikes the surface

Refractive index- expression of medium density

24
Q

When light enters a more dense medium is bends toward what?

A

Normal (90°)

25
Q

What is the critical angle?

A

In a dense medium leaving to a less dense medium, the angle at which total internal reflection occurs.

26
Q

What types of mediums have higher refractive indexes?

A

More dense mediums

27
Q

What is the refractive index of immersion oil and what is its purpose?

A

1.52 (same as crown glass)

Prevents the loss of light rays because the refractive index doesn’t change so the rays are less scattered. More light makes it to the lens.

28
Q

What is resolution?

A

The ability of a lens to discern fine detail (tell two points apart).

29
Q

What is resolution dependent on?

A

Wavelength and numerical aperture

30
Q

What is the equation to calculate resolution?

A

R = wavelength/2NA

31
Q

How does wavelength affect resolution?

A

The shorter the wavelength the more separation.

But it is a range (visible light).

32
Q

What is numerical aperture?

A

The ability of a lens to gather light.

33
Q

How does numerical aperture affect resolution?

A

The bigger the bundle of light (NA) the better the resolution.

34
Q

What does numerical aperture depend on?

A

The refractive index of the medium.

35
Q

What objective lenses have higher numerical apertures?

A

100x is the greatest (increases with mag)

36
Q

What does setting Kohler do?

A

Matches the NA of the condenser to that of the objective to provide the best resolution.

37
Q

What is the optimum useful magnification?

A

The highest magnification and resolution, any magnification higher loses resolution (empty mag)

38
Q

How is useful and empty magnification calculated?

A

Useful- NAx10^3 > total mag

Empty- NAx10^3

39
Q

What markings are found on the objective lenses?

A 
Magnification
NA
Tube length
Coverslip thickness
Oil immersion
Aberration corrections
40
Q

What working distance are infinity corrected objectives focused at?

A

1F

41
Q

What does an infinity lens allow the use of?

A

Filters and polarizers

42
Q

What must an infinity lens be used with?

A

A microscope with a tube lens.

43
Q

What two types of lenses are there and how do they affect light?

A

Convex- converge rays, magnification

Concave- diverge rays

MEDL 210 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions