Which objective lens provides the highest total magnification?
A.
High power
B.
Oil immersion
C.
Low power
D.
Scanning
The Correct answer and Explanation is:
The correct answer is:
B. Oil immersion
Explanation:
In microscopy, the total magnification is determined by the combination of the objective lens and the ocular lens (eyepiece). The total magnification is calculated by multiplying the magnification power of the objective lens by that of the ocular lens. For example, if the ocular lens has a magnification of 10x, the total magnification with each objective lens can be calculated as follows:
- Scanning Objective Lens (4x): This lens is used to quickly locate the specimen on the slide. When combined with a 10x ocular lens, the total magnification is 40x (4x objective lens × 10x ocular lens).
- Low Power Objective Lens (10x): This lens provides a broader field of view than higher magnification lenses and is useful for examining larger areas of the specimen. When combined with a 10x ocular lens, the total magnification is 100x (10x objective lens × 10x ocular lens).
- High Power Objective Lens (40x): This lens offers greater detail and magnification compared to the scanning and low power lenses. When combined with a 10x ocular lens, the total magnification is 400x (40x objective lens × 10x ocular lens).
- Oil Immersion Objective Lens (100x): This lens provides the highest level of magnification among the typical objective lenses used in a light microscope. It is designed to be used with immersion oil, which has a refractive index similar to glass, reducing light refraction and allowing for higher resolution. When used with a 10x ocular lens, the total magnification is 1000x (100x objective lens × 10x ocular lens).
The oil immersion lens offers the highest total magnification because it has the greatest magnification power (100x) among the standard objective lenses. The use of oil immersion allows for increased resolution and clarity at this high level of magnification, making it ideal for observing fine details in specimens. Thus, it provides the highest total magnification compared to scanning, low power, and high power objective lenses.