microscope

What is total magnification?

How much bigger the specimen appears.

How do you calculate total magnification?

Eyepiece × objective.

What is the usual eyepiece magnification?

10×

What is the total magnification with a 10× eyepiece and 4× objective?

40×.

What is the total magnification with a 10× eyepiece and 10× objective?

100×.

What is the total magnification with a 10× eyepiece and 40× objective?

: 400×.

What is the total magnification with a 10× eyepiece and 100× objective?

1,000×.

If total magnification is 400× and the eyepiece is 10×, what is the objective?

40×.

What happens to the specimen when magnification increases?

The specimen looks bigger.

What happens to the field of view when magnification increases?

It gets smaller

What is field of view?

The amount of the specimen you can see.

At low magnification, do you see more or less of the specimen?

more

At high magnification, do you see more or less of the specimen?

Less.

Which magnification gives you a larger field of view?

Low magnification.

Which magnification gives you a smaller field of view?

High magnification

Which objective should you start with?

The lowest-power objective.

Why start with the lowest power?

It makes the specimen easier to find and focus.

What does coarse adjustment do?

Makes large focus changes.

What does fine adjustment do?

Makes small focus changes and sharpens the image.

Which focus knob is used mainly on low power?

Coarse adjustment.

Which focus knob should be used on high power?

Fine adjustment.

Why should you avoid coarse adjustment on high power?

It can move the lens too much and damage the slide or lens.

Does a compound microscope show the image normally or inverted?

Inverted/reversed.

If you move the slide right, which way does the image move?

Left

If you move the slide left, which way does the image move?

right

If you move the slide up, which way does the image move?

down

If you move the slide down, which way does the image move?

up

What is the easy rule for image movement?
.

The image moves opposite the direction you move the slide.

What happens if there is too much light?

The specimen can look washed out/too bright.

What happens if there is too little light?

The specimen looks too dark.

What controls the amount of light passing through the specimen?

The diaphragm

What focuses light onto the specimen?

The condenser.

How should you carry a microscope?.

With two hands—one holding the arm and one supporting the base.

How should you clean microscope lenses?

With lens paper.

Should you touch the lenses with your fingers?

no

Why shouldn't you touch the lenses?.

Fingerprints and oils can damage or dirty the lenses.

What should you do before putting the microscope away?

Return it to the lowest-power objective and properly store it.

What should you do with the microscope's power/light after use?

turn it off

What is the specimen placed on?

A microscope slide.

What covers the specimen on a slide?

A coverslip.

Why is a coverslip used?

It protects the specimen and helps keep it in place.

What should you do if you lose the specimen while switching to higher magnification?

Go back to low power, find and center it, then increase magnification again.

Why should you center the specimen before increasing magnification?

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The field of view becomes smaller, so the specimen can disappear from view

Total magnification =

Eyepiece × Objective

Higher magnification →

bigger image + smaller field of view

Lower magnification →

smaller image + larger field of view

Coarse =

BIG focus changes

Fine =

SMALL focus changes

High power →

use FINE adjustment

Move slide right →

image goes left

Move slide left →

image goes right

Move slide up →

image goes down

Move slide down →

image goes up

Diaphragm →

controls light

Condenser → t

focuses light

Carry microscope →

arm + base

Clean lenses →

lens paper

start with low or high power?

Start with LOW power