electron microscope pdf

It is a sophisticated form of microscope, which can provide a higher magnification of the object (up to 1,00,000 times or more). The electron microscope employs an electron beam emanating from a cathode, instead of light as in the compound microscope..

In optical microscope, the ray of light can be bent by a lens system. By placing the object and the lens system in such a way, we control the direction of the ray to get a magnified image of the object. Since as 'electron' carriers charge it is possible to change the direction o..

It is used for the study of three-dimensional surface view of a given specimen. Its resolving power is also around 2 to 10 0 A. fig. 3.5 - Scanning Electron Microscope..

Dual Nature of Radiation and Matter..

Small drops of oil formed by a sprayer are allowed to fall in between a positively charged upper metal plate and a negatively charged lower metal plate. The space between the two plates is irradiated with X-rays. This displaces some electrons of the air molecules, which consequently get ..

The optical microscopes developed in physics are extensively used in the study of biological samples. Electron microscope, X-rays and radio isotopes are used widely in medical scienc..

It is a system of highly branching membranes, which almost fills the space inside the cell membrane. Some of the branches of endoplasmic reticulum are connected to the plasma membrane while some of them are connected to the nuclear membrane. An examination of endoplasmic reticulum under the el..

This is a prominent, spherical or oval structure found at the centre of the cell. It is the controlling centre of all cell activities and has been described as the brain of the cell. It regulates all metabolic and hereditary activities of the cell. The nucleus is composed of the following structur..

Question 1 - Question: Why were the scientists not able to observe most of the cell organelles before 1940? Answer: Before 1940, scientists could view the cell only under a light microscope. The invention of the electron microscope in 1940 enabled the scientists to obs..