MLT 81 Chapter 5 Quiz A

What is the purpose of the condenser in a microscope?

• To control the amount of light passing through the material

• To magnify the image formed by the objective

• To adjust the focus on the ocular

• To regulate the area of the circle of light in the field of view

Answer explanation

The condenser in a microscope is used to control the amount of light that passes through the material being observed. This is crucial as it allows for better visibility and clarity of the specimen under examination. Therefore, the purpose of the condenser is not to magnify the image, adjust the focus on the ocular, or regulate the area of the circle of light in the field of view.

What is the total magnification of an object seen with a 10× ocular and a 10× objective?

• 10×

• 20×

• 100×

• 200×

Answer explanation

The total magnification of an object seen through a microscope is calculated by multiplying the magnification of the ocular lens by the magnification of the objective lens. In this case, both the ocular and objective lenses have a magnification of 10×. Therefore, the total magnification is 10× * 10× = 100×.

What is the function of the aperture iris diaphragm in a microscope?

• To control the amount of light passing through the material

• To magnify the image formed by the objective

• To adjust the focus on the ocular

• To regulate the area of the circle of light in the field of view

Answer explanation

The aperture iris diaphragm in a microscope functions to control the amount of light passing through the material. This is crucial as it allows for better visibility and clarity when observing the material under the microscope. The other options, such as magnifying the image or adjusting the focus, are not the primary functions of the aperture iris diaphragm.

What is the purpose of the field iris diaphragm in a microscope?

• To control the amount of light passing through the material

• To magnify the image formed by the objective

• To adjust the focus on the ocular

• To regulate the area of the circle of light in the field of view

Answer explanation

The iris diaphragm in a microscope is used to regulate the area of the circle of light in the field of view. It is not used to control the amount of light passing through the material, magnify the image formed by the objective, or adjust the focus on the ocular. Therefore, the correct answer to the question is that the iris diaphragm is used to regulate the area of the circle of light in the field of view.

What is the numerical aperture (NA) of a microscope objective?

• The light-gathering ability of the objective

• The magnification strength of the objective

• The distance from the object being viewed to the lens

• The number of highly diffracted image-forming light rays captured by the objective

Answer explanation

The numerical aperture (NA) of a microscope objective refers to the number of highly diffracted image-forming light rays captured by the objective. It is not about the light-gathering ability, magnification strength, or the distance from the object to the lens. Therefore, the correct answer is 'The number of highly diffracted image-forming light rays captured by the objective'.

What is the purpose of the ocular in a microscope?

• To control the amount of light passing through the material

• To magnify the image formed by the objective

• To adjust the focus on the ocular

• To regulate the area of the circle of light in the field of view

Answer explanation

The ocular, also known as the eyepiece, in a microscope serves the purpose of magnifying the image formed by the objective lens. It does not control the amount of light, adjust the focus on itself, or regulate the area of the circle of light in the field of view. Therefore, the correct answer to the question is that the ocular is used to magnify the image formed by the objective.

What is the function of the base in a microscope?

• To control the amount of light passing through the material

• To support the magnifying and adjusting systems

• To adjust the focus on the ocular

• To regulate the area of the circle of light in the field of view

Answer explanation

The base of a microscope serves as the foundation of the device, providing stability and support for the magnifying and adjusting systems. It does not control the amount of light, adjust the focus on the ocular, or regulate the area of the circle of light in the field of view.

What is the purpose of the stage in a microscope?

• To control the amount of light passing through the material

• To magnify the image formed by the objective

• To adjust the focus on the ocular

• To hold the object being observed

Answer explanation

The stage in a microscope serves the purpose of holding the object that is being observed. It does not control the amount of light passing through the material, magnify the image formed by the objective, or adjust the focus on the ocular. Its primary function is to provide a platform where the specimen can be placed and observed under the microscope.

What are the three critical design characteristics of microscope objectives?

• Wavelength of light, angular aperture, and refractive index

• Magnification, resolution, and field of view

• Condenser size, objective lens type, and eyepiece magnification

• Objective lens material, condenser shape, and light source intensity

Answer explanation

The three critical design characteristics of microscope objectives are the wavelength of light, angular aperture, and refractive index. The wavelength of light affects the resolution, the angular aperture determines the amount of light that can enter the lens, and the refractive index influences the light's direction. These factors are crucial for the microscope's performance.

What is the purpose of the low-power objective?

• To gather light passing through a specimen and project an image

• To provide rapid movement for focusing

• To study histologic sections and wet preparations in detail

• To scan and observe specimens during initial examination

Answer explanation

The purpose of the low-power objective in a microscope is to scan and observe specimens during the initial examination. This is the first step in microscopy, allowing for a broad view of the specimen before moving to higher magnification for detailed study.