Microscopes

Question 1

Formula for TOTAL MAGNIFICATION

Answer 1

TOTAL MAGNIFICATION =

OCULAR LENS MAGNIFICATION

                    X 

OBJECTIVE LENS MAGNIFICATION

Question 2

WHCI Ocular Lens =

Answer 2

10X

Question 3

Low Power Objective Lens Magnification =

Answer 3

4X

Question 4

Medium Power Objective Lens Magnification =

Answer 4

10X

Question 5

High Power Objective Lens Magnification =

Answer 5

40X

Question 6

ACTUAL SIZE FORMULA

Answer 6

ACTUAL SIZE =

FIELD OF VIEW (FOV)

DIVIDED BY

# OF TIMES CELL FITS ACROSS FOV

Question 7

WHCI Microscope FOV Diameters

Low

Answer 7

Low = 4 mm/4000 μm

Question 8

WHCI Microscope FOV Diameters

Medium

Answer 8

Medium = 1.6 mm/1600 μm

Question 9

WHCI Microscope FOV Diameters

High

Answer 9

High = 0.4 mm/400 μm

Question 10

DRAWING MAGNIFICATION FORMULA

Answer 10

DRAWING MAGNIFICATION =

DRAWING SIZE (in mm)

divided by
ACTUAL SIZE (in mm)

Question 11

What is the function of a BASE on a microscope?

Answer 11

this is the bottom of the microscope, used for support

Question 12

What is the function of a ARM on a microscope?

Answer 12

supports the tube and connects it to the base

Question 13

What is the function of a STAGE on a microscope?

Answer 13

supports the microscope slide

has a central opening that allows light to pass through the slide

Question 14

What is the function of CLIPS on a microscope?

Answer 14

hold the slide in position on the stage

Question 15

What is the function of DIAPHRAGM on a microscope?

Answer 15

controls the amount of light that reaches the object being viewed

Question 16

What is the function of a OBJECTIVE LENSE on a microscope?

Answer 16

magnify the object

typically have three possible magnifications: low (4x), medium (10x) and high power (40x)

Question 17

What is the function of a REVOLVING NOSEPIECE on a microscope?

Answer 17

holds the objective lenses

rotates, allowing the objective lenses to be changed

Question 18

what is the function of a BODY TUBE on a microscope?

Answer 18

contains the eyepiece (ocular lens)
supports the objective lenses

Question 19

What is the function of a EYEPIECE (OCULAR LENS) on a microscope?

Answer 19

this is the part that you look through to view the object

magnifies the image of the object, usually by 10x

Question 20

What is the function of a COARSE ADJUSTMENT KNOB on a microscope?

Answer 20

moves the stage up or down to get the object into focus

is used with the low-power objective lens only

(bigger knob)

Question 21

What is the function of a FINE ADJUSTMENT KNOB on a microscope?

Answer 21

moves the tube to get the object into sharp focus

is used with medium-power and high-power magnification

is used only after the object has been located, centered and focused under low power magnification using the coarse-adjustment knob

(smaller knob)

Question 22

What is the function of the LIGHT SOURCE/LAMP on a microscope?

Answer 22

may be an electric light bulb or a mirror that can be angled to direct light through the object being viewed

Question 23

Precautions NEEDED to know when handling the microscope

Answer 23

Handling the Microscope:

Clean the lens as needed using lens paper ONLY

Carry the microscope by the base and arm – always use 2 hands

When finished with the microscope, always put it away with the stage lowered all the way and the lowest power objective in place

Question 24

Precautions needed to know when Adjusting the light on a microscope

Answer 24

Adjusting the Light

Use the diaphragm to regulate the amount of light coming through the specimen.
Too much light will not allow the contrast that is often necessary to see the required detail.

Question 25

Precautions needed to know when focusing a microscope

Answer 25

ALWAYS begin with the lowest power objective lens in place.

Focus with the Coarse Adjustment Knob first and then the fine adjustment know if necessary

Bring the medium power objective into place and focus with the fine adjustment only

Bring the high power objective into place and focus with the fine adjustment only