M315 Final Flashcards
Describe the position of your hands when carrying the microscope to and from your laboratory bench.
Both hands should be used– one holding the bottom of the microscope and one holding the arm
Differentiate between the limit of resolution of the typical light microscope and that of the unaided human eye.
light microscope = 0.2 um
unaided human eye = 0.2 mm
What two adjustments can be made to the condenser?
height and diaphragm
What effect does adjusting the height of the condenser have?
When the condenser is raised, the amount of light on the slide is increased.
What effect does opening the diaphragm have?
When the diaphragm is open, the amount of light on the slide is increased.
Why are condenser adjustments preferred over the use of the light intensity control?
Condenser adjustments increase light without affecting the bulb light.
Why is it necessary to use oil in conjunction with the oil immersion lens and not with the other objectives?
The small working distance does not let enough let in alone and the oil is needed to direct more light into the lens. The oil has the same refractive index as glass.
What is the relationship between the working distance of an objective lens and its magnification power?
When the power of the objective lens increases, the working distance decreases.
Objective lens provides that provides the highest magnification
oil immersion
Objective lens that provides the second-highest magnification
high-dry (40x)
Objective lens that provides the lowest magnification
low power (5x)
This objective lens has the shortest working distance
oil immersion
The coarse focus knob should be adjusted only when using this objective lens
low power
This lens collects and focuses light from the lamp onto the specimen on the slide
condenser
This lens, also known as the eyepiece, often comes in pairs
ocular
Diopter adjustments can be made to this lens
ocular
A diaphragm is used to regulate light passing through this lens
condenser
TRUE or FALSE: Acetone is the safest solvent for cleaning an objective lens
FALSE– acetone is a powerful solvent that could possibly dissolve the lens mounting cement if used too liberally
TRUE or FALSE: only lint-free, optically safe tissue should be used to wipe off microscope lenses
TRUE
TRUE or FALSE: once focus in achieved at one magnification, a higher-power objective lens can be rotated into position without fear of striking the slide
TRUE
The resolving power of a microscope is a function of…
The magnifying power of the lenses and the numerical aperture of the lenses
The coarse and fine focus knobs adjust the distance between…
The stage and the objective lens
A microscope that maintains focus when the objective magnification is increased is called…
parfocal–hence why the microscope does not lose focus when increasing magnification
The total magnification achieved when using a 100 x oil immersion lens with 10 x binocular eyepieces is…
1000 x