18 Questions
What is the primary reason why high magnification is required in microbiological work?
To examine microorganisms in detail
What is the function of the sub-stage condenser with diaphragm in a microscope?
To control the focus of the light on the object and adjust the diameter of the circle of light
What is the total magnification power of a microscope with an eyepiece of 10X and an objective of 40X?
400X
What is the highest magnification obtainable with a compound light microscope?
1000X
What type of microscope is used for routine microbiological work?
Compound light microscope
What is the purpose of the body tube in a microscope?
To contain the ocular and objective lenses
Why is increasing magnification above 1000X of no advantage in a compound light microscope?
Because the resolving power is not increased
What is the function of the ocular lens in a microscope?
To provide 10X magnification
What is the purpose of the objective lens in a microscope?
To provide all of the above
What is the main difference between a compound light microscope and other types of microscopes?
Presence of both ocular and objective lens systems
What is the purpose of the clip in light in a microscope?
To provide illumination for the sample
What happens to the resolving power of a microscope if the magnification is increased beyond 1000X?
It is not affected
What is the function of the diaphragm in a microscope?
To regulate the diameter of the circle of light leaving the condenser
What is the purpose of using an oil immersion objective lens in a microscope?
To improve the resolving power
What is the main advantage of using a compound light microscope in microbiological work?
High magnification power
What is the relationship between the magnification power of the ocular lens and the objective lens in a compound light microscope?
They are multiplicative
What is the purpose of the body in a microscope?
To support the microscope
What is the difference between a phase-contrast microscope and a fluorescent microscope?
Illumination system used
Study Notes
Microscope Components
- The body of the microscope supports all the components
- The body tube contains the ocular and objective lenses
Lenses and Magnification
- Ocular or eyepiece lens has a 10X magnification
- Objective lens has three types of magnification:
- Low power: 10X
- High power: 40X
- Oil immersion: 100X
- Total magnification power is the product of the ocular and objective lens systems
- Example: 10X eyepiece and 40X objective lens = 400X total magnification
Microscope Functionality
- Sub-stage condenser with diaphragm controls the focus of light on the object
- Diaphragm controls the diameter of the circle of light leaving the condenser
Limitations of Microscope
- Highest magnification obtainable with a compound light microscope is about 1000X
- Increasing magnification above 1000X is of no advantage if the resolving power is not also increased
- Resolving power is the capacity to distinguish two neighbouring points as separate entities
This quiz covers the different parts of a microscope, including the body, lenses, and sub-stage condenser. It also explains how to calculate total magnification and the limitations of microscope usage.
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