What is total magnification when you use 10X ocular lens and 40X objective lens?

Microscopes magnify the tiniest inhabitants of this world. From the minute details of cells to the delicate cilia of paramecium to the intricate workings of Daphnia, microscopes reveal many miniscule secrets. Calculating total magnification uses simple observation and basic multiplication.

Basic Microscope Design

Microscopes use lenses to magnify objects. A simple microscope uses only one lens; a magnifying glass could be called a simple microscope. The magnification of a simple microscope doesn't need any calculation because the single lens is usually labeled. A hand-lens, for example, might be labeled with 10x, meaning the lens magnifies the object to look ten times larger than the actual size.

Compound microscopes use two or more lenses to magnify the specimen. The standard school microscope combines two lenses, the ocular and one objective lens, to magnify the object. The ocular or eyepiece is found at the top of the body tube. The objective lens points down toward the object to be magnified. Most microscopes have three or four objective lenses mounted on a rotating nosepiece. Rotating the nosepiece lets the viewer change the magnification. Different objective lenses provide different magnification options.

Finding Lens Magnification

Finding the magnification of each lens requires examining the casing of each lens. On the side of the casing is a series of numbers that includes a number followed by x, as 10x. This 10x shows that the lens magnifies an object to appear ten times larger than reality. Depending on the manufacturer, this magnification number may appear at the beginning or at the end of the number sequence. To calculate total magnification, find the magnification of both the eyepiece and the objective lenses. The common ocular magnifies ten times, marked as 10x. The standard objective lenses magnify 4x, 10x and 40x. If the microscope has a fourth objective lens, the magnification will most likely be 100x.

Calculating Magnification

Once the magnification of each individual lens is known, calculating total magnification is simple math. Multiply the magnification of the lenses together. For example, if the eyepiece magnification is 10x and the objective lens in use has a magnification of 4x, the total magnification is:

10\times 4 = 40

The total magnification of 40 means that the object appears forty times larger than the actual object. If the viewer changes to the 10x objective lens, the total magnification will be the ocular's 10x magnification multiplied by the new objective lens's 10x magnification, calculated as:

10\times 10 = 100

Note that calculating magnification in telescopes uses a different equation than calculating magnifiction in microscopes. For telescopes, one magnification calculation uses the focal lengths of the telescope and the eyepiece. That calculation is:

\text{magnification}=\frac{\text{focal length of telescope}}{\text{focal length of eyepiece}}

Like the microscope, these numbers usually can be found on the telescope.

Remember, in lecture that we talk about the fact that shorter wavelengths (blue range of visible light or even shorter UV light or electrons, which have an even shorter wavelength than light) and larger numerical aperture provide the greatest resolution. So, even without using the formula, you can deduce that a decrease in wavelength would increase resolution. However, you can also see this mathematically by playing with the formula:

For example:

RP = 400 nm = 160 nm 400 nm is the wavelength of light in the violet range and 1.25 is the
2 x 1.25 numerical aperture of the 100x objective lens.
RP = 200 nm = 80 nm 200 nm is the wavelength of light in the UV range and 1.25 is the
2 x 1.25 numerical aperture of the 100x objective lens.

Also, remember that nanometers (nm) are very small units of measurement, below micrometers
(µm), millimeters (mm), meters (m), etc. We usually measure microbes in micrometers (µm).

Students also viewed

The Elements of Life

In biology, the elements of life are the essential building blocks that make up living things. They are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. The first four of these are the most important, as they are used to construct the molecules that are necessary to make up living cells. These elements form the basic building blocks of the major macromolecules of life, including carbohydrates, lipids, nucleic acids and proteins. Carbon is an important element for all living organisms, as it is used to construct the basic building blocks of life, such as carbohydrates, lipids, and nucleic acids. Even the cell membranes are made of proteins. Carbon is also used to construct the energy-rich molecules adenosine triphosphate (ATP) and guanosine triphosphate (GTP). Hydrogen is used to construct the molecules water and organic compounds with carbon. Hydrogen is also used to construct ATP and GTP. Nitrogen is used to construct the basic building blocks of life, such as amino acids, nucleic acids, and proteins. It is also used to construct ATP and GTP. Oxygen is used to construct the basic building blocks of life, such as carbohydrates, lipids, and nucleic acids. It is also used to construct ATP and GTP. Phosphorus is used to construct the basic building blocks of life, such as carbohydrates, lipids, and nucleic acids.

What is the total magnification when using a 40x ocular lens and 40x objective lens?

What is the total magnification of 4x 10x and 40x?

What is the total magnification if you are observing an object with 4x 10x 40x objective lens?

What 10x and 40x signifies in a microscope?