Question

The microscope that gives the greatest resolution, and therefore the highest useful magnification is the:  

A. compound light microscope;  

B. transmission electron microscope;  

C. darkfield microscope;  

D. scanning electron microscope;  

E. fluorescence microscope.

Answer 1

Ans: Transmission electron microscope

Explanation: Electron microscope that gives the greatest resolution, and therefore the highest useful magnification. The normal optical microscope uses light to magnify images up to 2000x and it has resolution upto 200 Nanometer, but electron microscope uses electrons for the magnification of images upto 10,000,000x with 50 picometer resolution. Electron microscope is more expensive than an ordinary microscope. There are three forms of electron microscope ie, Transmission electron microscope, Scanning electron microscope and Scanning tunnel microscopy.

Transmission electron microscope: It is an electron microscope that uses a high voltage beam of electrons for the high magnification and resolution of images. It has the highest magnification capacity. It can be used only on thin samples and images are obtained on photographic plate, sensor, or fluorescent screen. It is the first electron microscope.

The scanning electron microscope uses a beam of electrons to scan the sample, and the beam of electron across the surface of the sample which leads to formation of images by a secondary electron that is emitted by the surface of the samples. SEM gives the three dimensions images of samples and it can be used on thick samples. SEM have less magnification than TEM.

Hence option b is correct.