$\text{Objective lens magnification} \times \text{Ocular lens magnification}$

Question 1

Which of the following best describes the correct way to carry a compound light microscope?

Accepted Answer

Carry the microscope with one hand under the base and the other hand on the neck.

Question 2

If the objective lens is 40x and the ocular lens is 10x, what is the total magnification of the microscope?

Accepted Answer

$40 	imes 10 = 400$

Question 3

What is the function of the iris diaphragm in a compound light microscope?

Accepted Answer

It regulates the amount of light and contrast passing through the specimen.

Question 4

Which part of the microscope should you use to bring a specimen into sharp focus under high power?

Accepted Answer

Fine adjustment knob

Question 5

A student switches from the 4x objective lens to the 40x objective lens. What happens to the field of view?

Accepted Answer

The field of view decreases.

Question 6

Which term describes the ability of a microscope to distinguish two close objects as separate?

Accepted Answer

Resolving power

Question 7

Why should you avoid using the coarse adjustment knob when switching to a higher power objective lens?

Accepted Answer

It can break the slide or damage the lens due to the reduced working distance.

Question 8

What is the working distance in microscopy?

Accepted Answer

The distance between the objective lens and the specimen.

Question 9

A microscope is described as 'parfocal.' What does this mean?

Accepted Answer

The specimen remains mostly in focus when switching between objective lenses.

Question 10

If you want to increase the contrast of your specimen, what should you do with the iris diaphragm?

Accepted Answer

Close the iris diaphragm to allow less light.

Question 11

Which of the following is a correct step when starting to view a new slide under the microscope?

Accepted Answer

Start with the stage down and the 4x objective lens.

Question 12

A student observes a specimen under low power and then switches to high power. The specimen is no longer in focus. What is the most likely reason?

Accepted Answer

The microscope is not parfocal.

Question 13

Which formula correctly calculates the total magnification of a microscope?

Accepted Answer

$	ext{Objective lens magnification} 	imes 	ext{Ocular lens magnification}$

Question 14

Which part of the microscope is responsible for holding and rotating the objective lenses?

Accepted Answer

Revolving nosepiece

Question 15

What is the main reason for cleaning microscope lenses only with lens paper and cleaner?

Accepted Answer

To avoid scratching or damaging the delicate lens surfaces.

Question 16

Which scenario best illustrates the concept of 'depth of field' in microscopy?

Accepted Answer

Observing multiple layers of a specimen in sharp focus at the same time.

Question 17

A student wants to observe fine details in a thin tissue section. Which combination of settings will best achieve this?

Accepted Answer

High power objective lens, fine adjustment knob, and increased light intensity.

Question 18

Why is it important to store the microscope with the lowest power objective lens in position?

Accepted Answer

It reduces the risk of damaging the lens or slide when next used.

Question 19

Which of the following best explains why the field of view decreases as magnification increases?

Accepted Answer

Higher magnification narrows the area visible through the lens.

Question 20

A researcher needs to distinguish two bacteria that are very close together. Which property of the microscope is most critical for this task?

Accepted Answer

Resolving power

Lab 4: Care, Handling, and Use of the Microscope

Study Guide - Practice Questions