What is the basic principle of electron microscope?

A diffraction pattern is obtained using a beam of red light.What happens if the red light is replaced by blue light ?

The De-Broglie wavelength of a neutron of kinetic energy $\mathrm{K}$ is $\mathrm{\lambda }$. When its kinetic energy is $4 \mathrm{K}$, what is the De-Broglie wavelength of the neutrons?

What is the de Broglie wavelength of a bullet of mass $0.040 \mathrm{Kg}$ travelling at the speed of $1.0 \mathrm{Km}/\mathrm{s}$?

A plano-convex lens of radius $3 \mathrm{m}$ is placed on an optically flat glass plate and is illuminated by monochromatic light. The radius of the $8^{\mathrm{th}}$ dark ring is $3.6 \mathrm{mm}$. Calculate the wavelength of light used.

The threshold frequency of a photo-sensitive surface is $5\times {10}^{14} \mathrm{Hz}$. Then which of the following can produce photoelectric emission from the same surface?

What is the de Broglie wavelength of a ball of mass $0.060 \mathrm{Kg}$ moving at a speed of $1.0 \mathrm{m}/\mathrm{s}$?

 Electron microscope is used to view low resolution images of biological and non-biological specimens.

1. Describe how can a microscope be used to observe some blood cells. 

Copy and complete the table which compares light microscope with an electron microscope.