A&p Lab, Microscope (10 Question Pt 2)

Explanation
The movable nose piece is responsible for carrying the objective lenses and allows them to be rotated into position over the specimen. This allows the user to easily switch between different objective lenses and adjust the magnification levels while observing the specimen.

Explanation
The distance from the bottom of the objective lens in use to the specimen is called the working distance. This distance is important in microscopy as it determines the amount of space available for manipulating the specimen and for the passage of light. A shorter working distance means that the objective lens needs to be closer to the specimen, while a longer working distance allows for more space between the lens and the specimen.

Explanation
To bring the object from the left side of the field to the center, you would need to move your slide to the right. By moving the slide towards the right, you are effectively shifting the object towards the apparent right side of the field, which is the center. Therefore, moving the slide to the right is the correct direction to bring the object to the center.

Explanation
When looking through a microscope, the area of the specimen that is visible is referred to as the "field." This term is used to describe the portion of the specimen that is in focus and can be observed under the microscope. The field may vary in size depending on the magnification of the microscope and the objective lens being used.

Explanation
The total magnification of a microscope is calculated by multiplying the magnification of the ocular lens (eyepiece) with the magnification of the objective lens. In this case, the ocular lens has a magnification of 10x and the total magnification is 950x. To find the magnification of the objective lens, we can divide the total magnification by the magnification of the ocular lens: 950/10 = 95. Therefore, the magnification of the objective lens is 95x.

Explanation
Dimming the light when looking at living (nearly transparent) cells helps to provide more contrast. This is because when the light is too bright, it can cause the cells to appear washed out or blend into the background, making it difficult to see the details and structures within the cells. By dimming the light, the contrast between the cells and the background is increased, allowing for better visualization and analysis of the cells.

Explanation
A microscope is said to be parfocal if, after focusing in low power, only the fine adjustment is needed to focus the specimen at higher powers. This means that once the specimen is in focus at low power, switching to higher powers will maintain the focus without the need for major adjustments. This feature is convenient as it saves time and allows for a smooth transition between different magnifications without losing focus.

Explanation
When using a 10x ocular and a 15x objective, the field size is 1.5 mm. This means that the total magnification is 10 x 15 = 150x. To find the approximate field size with a 30x objective, we can divide the total magnification by the objective magnification. So, 150x / 30x = 5. This means that the field size with a 30x objective is approximately 5 times larger than with a 15x objective. Since the field size with a 15x objective is 1.5 mm, the approximate field size with a 30x objective would be 1.5 mm x 5 = 7.5 mm, which can be rounded to .75 mm.

Explanation
If the size of the high-power field is 1.2 mm and the object occupies approximately a third of that field, it means that the object occupies 1/3 of 1.2 mm. To find the estimated diameter of the object, we can multiply 1/3 by 1.2 mm. This calculation gives us 0.4 mm. Therefore, the estimated diameter of the object is approximately 0.4 mm. 

Explanation
At low power, the depth of field is more extensive because the camera lens is set to a wider aperture, allowing more light to enter and a larger range of distances to be in focus. This results in a greater depth of field, meaning that objects both near and far from the camera will appear sharp and in focus. On the other hand, at high power, the depth of field becomes more restricted as the lens is set to a narrower aperture, allowing less light and narrowing the range of distances that will be in focus.

Explanation
At high power, the depth of focus is more restricted. This means that when using high power, the range of distances over which objects appear in focus is smaller compared to lower power. This is because high power magnifies the image, making it more difficult to maintain focus across a larger depth range. As a result, any slight movement or change in distance can cause objects to go out of focus more easily at high power.