What is the equation for total magnification?
a. Objective lens x ocular lens
b. Fine focus lens x ocular lens
c. Objective lens x fine focus lens
d. Course objective lens x fine focus lens
The correct answer and explanation is :
The correct answer is a. Objective lens x ocular lens.
Explanation:
Total magnification refers to the overall magnification power of a microscope, which is achieved by combining the magnification of the objective lens and the ocular (eyepiece) lens.
- Objective Lens: The objective lens is the primary lens of a microscope, located close to the specimen. It typically has multiple magnification levels, such as 4x, 10x, 40x, and 100x. These lenses are crucial for adjusting the zoom level and for focusing on different aspects of the specimen. The objective lens provides the initial magnification.
- Ocular (Eyepiece) Lens: The ocular lens is the lens you look through at the top of the microscope. It typically has a fixed magnification of 10x (although some can be 15x or more). The ocular lens helps to further magnify the image produced by the objective lens.
Total Magnification Calculation:
To calculate the total magnification, you multiply the magnification power of the objective lens by the magnification power of the ocular lens.
- For example, if you are using a 10x objective lens and a 10x ocular lens, the total magnification would be: [
\text{Total Magnification} = \text{Objective Lens Magnification} \times \text{Ocular Lens Magnification}
]
[
\text{Total Magnification} = 10 \times 10 = 100x
]
Thus, the image you see will be 100 times larger than the actual size of the object.
Why the Other Answers are Incorrect:
- b. Fine focus lens x ocular lens: The fine focus lens does not contribute to magnification; it only helps with focusing the image clearly.
- c. Objective lens x fine focus lens: The fine focus lens doesn’t affect magnification, it only aids in the precision of focusing.
- d. Course objective lens x fine focus lens: Like the fine focus lens, the coarse objective lens helps with focusing but not magnification.
In summary, the total magnification is determined by multiplying the magnification of the objective lens and the ocular lens, which is why option a is the correct answer.