Table of Contents
- 1 What objective lens has the greatest working distance?
- 2 Which objective of microscope focuses closest to the slide?
- 3 Which objective lens has the least working distance?
- 4 Which objective provides the greatest field of view?
- 5 What part of the microscope are the objectives attached to?
- 6 What is objective working distance?
- 7 What is the magnification power of an objective lens?
- 8 How do you get the right focus on a microscope?
What objective lens has the greatest working distance?
Working distance is greatest when the low power objective is in use. It is appropriate to use the course adjustment under low power. Working distance decreases as magnifying lenses are increased. Do not focus with the course adjustment when using the high dry objective (40X) or the oil immersion objective.
What part of the microscope is used for larger focusing?
Coarse Adjustment Knob- The coarse adjustment knob located on the arm of the microscope moves the stage up and down to bring the specimen into focus.
Which objective of microscope focuses closest to the slide?
Which objective focuses closest to the slide when it is in focus?
| Question | Answer |
|---|---|
| Why is it desirable that microscope objectives be parfocal | Bc if it is in focus in one lens than it is in all |
| Which objective focuses closest to the slide when it is in focus | 100x oil immersion |
At which objective will you have the greatest depth of focus?
The depth of focus is greatest on the lowest power objective. Each time you switch to a higher power, the depth of focus is reduced. Therefore a smaller part of the specimen is in focus at higher power. The amount of light transmitted to your eye is greatest at the low power.
Which objective lens has the least working distance?
As working distance is inversely proportional to the magnification, the more the magnification the least will be the working distance. So, the objective lens with 100X Magnification will have the least working distance and an objective lens with magnification 5X will have maximum working distance.
Which type of objective are you going to use in focusing a specimen?
When focusing on a slide, ALWAYS start with either the 4X or 10X objective. Once you have the object in focus, then switch to the next higher power objective.
Which objective provides the greatest field of view?
4x objective lens
The 4x objective lens has the lowest power and, therefore the highest field of view.
Which objective is always used first when focusing on a slide?
10X objective
When focusing on a slide, ALWAYS start with either the 4X or 10X objective. Once you have the object in focus, then switch to the next higher power objective. Re-focus on the image and then switch to the next highest power.
What part of the microscope are the objectives attached to?
Nosepiece: The upper part of a compound microscope that holds the objective lens. Also called a revolving nosepiece or turret.
Which objective should I start with when focusing on a specimen?
3. When focusing on a slide, ALWAYS start with either the 4X or 10X objective. Once you have the object in focus, then switch to the next higher power objective. Re-focus on the image and then switch to the next highest power.
What is objective working distance?
Microscope objectives are generally designed with a short free working distance, which is defined as the distance from the front lens element of the objective to the closest surface of the coverslip when the specimen is in sharp focus.
How is the objective positioned in a microscope?
THE OBJECTIVE SHOULD BE POSITIONED ABOUT 1/4″ – 3/8″ ABOVE THE SLIDE. 4. PLACE THE SLIDE ON THE MICROSCOPE STAGE SUCH THAT THE PORTION OF THE SLIDE YOU WANT TO VIEW IS UNDER THE OBJECTIVE. 5. FOCUS ON SPECIMEN, FIRST USING THE COARSE AND THEN THE FINE FOCUS CONTROLS.
What is the magnification power of an objective lens?
Magnification Power: The objective lens and the ocular or eyepiece lens are in combination responsible for magnification of the specimen being observed. Therefore, for 10X objective and 10X ocular the total magnification = 10 X 10 = 100X. This means that the specimen being observed is now 100X it’s actual size.
How is the resolution of an objective lens determined?
A very low resolution would result in a blurred image and would prevent proper observation of the specimen. While the total magnification is determined by both the objective and ocular lens, the resolution is determined by the objective lens alone.
How do you get the right focus on a microscope?
ONCE THE IMAGE IS IN FOCUS,COVER YOUR RIGHT EYE WITH THE INDEX CARD AND LOOK THROUGH THE OTHER OCULAR WITH YOUR LEFT EYE. ADJUST THE FOCUS OF THE LEFT OCULAR BY TURNING THE KNURLED KNOB ENCIRCLING THE OCULAR TO THE LEFT OR THE RIGHT. ONCE THIS IS COMPLETED YOU WILL HAVE MATCHING FOCUS IN BOTH OCULARS.