Q: If the field of view under a 10X objective is 2 mm, what will be the approximate field of view under a 40X objective, assuming the field of view is inversely proportional to magnification?

$$\frac{2\ \text{mm} \times 10}{40} = 0.5\ \text{mm}$$

Question 1

Which part of the compound microscope is responsible for gathering and focusing light from the illumination source onto the specimen?

Accepted Answer

Condenser

Question 2

A student is using a compound microscope with a 10X ocular lens and a 40X objective lens. What is the total magnification being used?

Accepted Answer

$$10 	imes 40 = 400$$

Question 3

When switching from low power to high power objective, which adjustment knob should you use to bring the specimen into sharp focus?

Accepted Answer

Fine focus knob

Question 4

Why is it important to avoid using paper towels to clean microscope lenses?

Accepted Answer

Paper towels are too coarse and can scratch the precision ground lenses.

Question 5

A student observes three threads on a slide using a compound microscope. As the student increases magnification, only one thread remains in sharp focus at a time. What concept does this illustrate?

Accepted Answer

Depth of field

Question 6

Which of the following best explains why oil immersion is used with 100X objectives in compound microscopes?

Accepted Answer

Oil increases the refractive index between the lens and specimen, reducing light loss and improving resolution.

Question 7

If the field of view under a 10X objective is 2 mm, what will be the approximate field of view under a 40X objective, assuming the field of view is inversely proportional to magnification?

Accepted Answer

$$\frac{2\ 	ext{mm} 	imes 10}{40} = 0.5\ 	ext{mm}$$

Question 8

Which adjustment should be made to the diaphragm when switching from low to high power objectives?

Accepted Answer

Open the diaphragm to allow more light through.

Question 9

A student is viewing a slide and notices that the image moves to the left when the slide is moved to the right. What is the reason for this phenomenon?

Accepted Answer

The microscope uses mirrors to project the image, causing it to appear reversed.

Question 10

Which of the following steps should be performed first when focusing a compound microscope?

Accepted Answer

Place the scanning objective in position and bring the stage up using the coarse focus knob.

Question 11

What is the primary function of the mechanical stage on a compound microscope?

Accepted Answer

To move the slide smoothly and precisely in different directions for viewing.

Question 12

If a specimen is not visible under the high power objective, but was visible under low power, what is the most likely cause?

Accepted Answer

The specimen is not centered in the field of view.

Question 13

Which lens is responsible for the initial magnification of the specimen in a compound microscope?

Accepted Answer

Objective lens

Question 14

A student is using a microscope and wants to increase the resolution. Which of the following actions will be most effective?

Accepted Answer

Switch to a higher power objective lens.

Question 15

What is the correct order of steps for focusing a specimen under high power using a compound microscope?

Accepted Answer

Focus under low power with coarse knob, center specimen, switch to high power, use fine focus knob.

Question 16

Which of the following best describes the function of the scanning objective lens?

Accepted Answer

It provides the lowest magnification and widest field of view for locating specimens.

Question 17

A student is using a binocular microscope and notices that the image is not aligned for both eyes. What adjustment should be made?

Accepted Answer

Use the diopter adjustment ring to focus each ocular separately.

Question 18

Why is it important to avoid spinning the fine focus knob excessively when using high power objectives?

Accepted Answer

It can strip the precision gears and damage the microscope.

Question 19

Which of the following statements about resolution in microscopy is correct?

Accepted Answer

Resolution is the ability to distinguish two points as separate objects.

Question 20

A student is preparing a slide and wants to observe the three-dimensional aspects of an object. Which technique should be used?

Accepted Answer

Focus through the specimen and build a series of optical sections.

Microscopy: Principles and Use of the Compound Microscope LAB 10

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