Question

Electrons used in electron microscope are of wavelength

• A. less than $1\mathring{\text{A}}$
• B. more than $5000\mathring{\text{A}}$
• C. $2500\mathring{\text{A}}\text{to}5000\mathring{\text{A}}$
• D. All of the above

Answer 1

The correct option is A less than $1\mathring{\text{A}}$

The resolving power of a microscope is given by,

$RP=\frac{2\mu \sin \theta }{1.22\lambda }$

To have higher resolving power, the wavelength should be as small as possible.
Electron microscope uses a beam of electrons as a source of illumination instead of light. The beam of electrons has a wavelength of $0.54\mathring{\text{A}}$
Hence, $\left(A\right)$ is the correct answer.