This is the most advanced form of microscope. Its resolving power is 250 times or more that of a compound microscope. In this microscope, a beam of electrons under high voltage is passed through the object and its image is reflected on to a screen through an electro magnetic lens to make a photograph.
With the help of microscope, any object an be magnified up to 250,000 its original size.
COMPRISON OF LIGHT MICROSCOPE AND ELECTRON MICROSCOPE
- The radiation source is light so it is called light microscope.
- Wavelength of light is 400 – 700 nm.
- Maximum resolution is 200 nm.
- Maximum useful magnification is X 1500 with eye.
- Lenses are used.
- The radiation source is beam of electrons, so it is called Electron Microscope.
- Wavelength of beam of electrons is 0.005 nm.
- Maximum resolution is 0.5 nm.
- Maximum useful magnification is X. 250,000 on screen as image or photograph.
- Electromagnets are used.