Question

Explain the structure and principle used in light microscopes.

Answer 1

A light microscope is a laboratory instrument or tool for biology that uses visible light to detect and magnify, and enlarge, very small objects. To concentrate light on the specimen, they use lenses to magnify it, thus generating an image. Normally, the specimen is positioned next to the microscopic lens.

Complete answer:

A light microscope is a laboratory instrument or tool for biology that uses visible light to detect and magnify, and expand, very small objects.
To concentrate light on the specimen, they use lenses to magnify it, thus generating an image. Normally, the specimen is positioned next to the microscopic lens.
Depending on the styles and number of lenses that make up the microscope, microscopic magnification varies greatly.
There are two types of microscopes I based on the number of lenses. The compound light microscope (it has a low magnification because it uses a single lens) and the compound light microscope (it has a higher magnification compared to the simple microscope because it uses at least two sets of lenses, an objective lens and an ocular lens). The lenses are aligned in that they can bend light for the image to be efficiently magnified.
The working of the light microscope is dependent on its ability to concentrate a beam of light to create an image through a sample which is very small and transparent. For viewing, the image is then passed through one or two lenses for magnification. The transparency of the specimen makes light easy and quick to penetrate. Specimens can range from cells to bacteria and other microbial particles.
By using a glass lens, light microscopes picture an image and magnification is determined by the capacity of the lens to bend light and concentrate it on the specimen that forms an image.
The beam bends at the interface, inducing refraction, when a ray of light travels through one medium into another. The refractive index, which is a measure of how much a material reduces the speed of light, measures the bending of light.
The direction and magnitude of light bending are determined by the refractive indexes of the two interface-forming mediums.
A medium with a lower refractive index such as glass to air generally speeds up the penetration of light and bends light away from the normal and generally slows down and bends toward the normal, perpendicular to the surface, when light is passed through a medium with a higher refractive index such as air to glass.
Microscopy operates exclusively with a resolution factor, whereby resolution is the ability of a lens to discern small objects tightly packed together.
A light microscope's resolution is defined by its lens system's numerical aperture and the wavelength of the light it uses; a numerical aperture is a description of the light wavelengths produced when the specimen is illuminated.

Note: This microscope is used widely in microbiology to view fixed and live specimens that have been stained with fundamental stains. This offers contrast under the microscope for easy visibility. It can also be used to classify cells of basic bacteria and parasitic protozoans like Paramecium.