Lab 1 Microscopes and Measurements

Question 1

What is the function of the Ocular Lens?

Answer 1

The lens located inside the eyepiece that is used to magnify a specimen. On binocular microscopes, thee distance between the two eyepieces containing the ocular lenses should be adjusted by each user/

Question 2

What is the function of the Objective Lens?

Answer 2

A series of lenses used to magnify a specimen located on the nosepiece just above the stage

Question 3

What is the function of the arm?

Answer 3

Used for a hand when carrying the instrument; the other hand should be placed under the base

Question 4

What is the function of the Coarse Focus Knob?

Answer 4

Roughly focuses the specimen by changing the distance between the objective lens and the specimen

Question 5

What is the function of the Light Source?

Answer 5

Emits light onto the specimen

Question 6

What is the function of the Blue Filter?

Answer 6

Increases resolution by reducing the wavelength of light

Question 7

What is the function of the Mechanical Stage? Which microscope is this part of?

Answer 7

Large, flat surface that supports the slide or specimen over the hole that admits light from below. It also allows for the movement of the slide using the mechanical stage knobs. It is part of the compound microscope.

Question 8

What is the function of the Mechanical Stage Knobs? Which microscope is this part of?

Answer 8

Moves the slide around the stage surface. It is part of the compound microscope.

Question 9

What does the Fine Focus Knob do?

Answer 9

Sharply focuses the specimen by changing the distance between the objective lens and specimen very precisely.

Question 10

What does the Condenser do? Which microscope is this part of?

Answer 10

Contains 2 lenses that focus light onto the specimen. It is part of the compound microscope.

Question 11

What is the function of the Iris Diaphragm? Which microscope is this part of?

Answer 11

Regulates the amount of light passing through the lenses in the condenser. Reducing the amount of light increases the visibility of semi-transparent objects. It is part of the compound microscope. It is part of the compound microscope.

Question 12

What is the function of the Iris Diaphragm lever? Which microscope is this part of?

Answer 12

Opens and closes the iris diaphragm. It is part of the compound microscope.

Question 13

What is the function of the Condenser Adjustment Knob? Which microscope is this part of?

Answer 13

Moves the condenser up or down. It is part of the compound microscope.

Question 14

What is the function of the Lamp Switch? Which microscope is this part of?

Answer 14

Turns the light on and off. It is part of the compound microscope.

Question 15

What is the function of the Lamp Intensity DIal? Which microscope is this part of?

Answer 15

.Adjusts the brightness of light produced by the light source. It is part of the compound microscope.

Question 16

What is the function of the Stage? Which microscope is this part of?

Answer 16

Large flat surface that supports the slide or specimen over the hole that admits light from below (T Light). It is part of the dissecting microscope.

Question 17

What is the function of the Main Switch? Which microscope is this part of?

Answer 17

Controls supply of power to the microscope. Must be in the “on” position for either light to work. It is part of the dissecting microscope.

Question 18

What is the function of the T Switch? Which microscope is this part of?

Answer 18

Turns the light below a specimen on and off. It is part of the dissecting microscope.

Question 19

What is the function of the I Switch? Which microscope is this part of?

Answer 19

Turns the light above a specimen on and off. It is part of the dissecting microscope.

Question 20

What is the function of the Stage Clips? Which microscope is this part of?

Answer 20

Holds a slide in-position over the stage. It is part of the dissecting microscope.

Question 21

What is the highest power on the TEM?

Answer 21

300 000x

Question 22

What is the highest power on the SEM?

Answer 22

300 000x

Question 23

What is the highest power of the Dissecting microscope?

Answer 23

40x

Question 24

What is the highest power of the Compound microscope?

Answer 24

1000x

Question 25

What are the two types of electron microscopes?

Answer 25

Transmission Electron Microscope and the Scanning Electron Microscope

Question 26

What is resolution and how do you improve it?

Answer 26

Resolution refers to the clarity of an image, for a microscope it is the minimum distance that two points of lines can be separated and still be distinguished as separate units. - Improved by shortening the length of wavelengths (Blue filter) - Lowering the amount of diffraction (scattering of light) with the help of immersion oil or other forms.

Question 27

What is contrast and how do you improve it?

Answer 27

Contrast is a quality that makes the image stand out better. - Adjust the condenser, - Special light microscope (different types of light/wavelength) - Staining the specimen with a dye - Reduce the amount of light passing, either by --a. Iris diaphragm --b.Iris diaphragm lever

Question 28

What is the formula for actual size?

Answer 28

Actual size = fraction of the field occupied / field diameter Example. Actual size = 1/4 x 2mm Actual size = 0.5mm

Question 29

What is the formula for the speed/movement of a specimen?

Answer 29

Distance/time, usually per second Example: 1.8mm in 20 seconds 1.8mm/20s = 0.09mm/s

Question 30

What is the formula for the magnification of a drawing?

Answer 30

magnification = size of drawing/actual size of specimen, same units = 120mm / 0.3mm which is 400x magnification