The resolving power of an electron microscope operated at 16 kV is R. The resolving power of the electron microscope when operated at 4 kV is

The resolving power of the electron microscope at 4 kV is 2R.

Resolving power is the ability of a microscope to separate two very close objects and display them as distinct. In electron microscopy, resolving power depends on the wavelength of electrons, which is determined by the accelerating voltage applied.

Formula for Resolving Power

Using de Broglie’s equation, the wavelength of an electron is:

λ = h / √(2meV)

This shows that wavelength λ is inversely proportional to √V. Resolving power (R) is inversely proportional to λ, so:

R ∝ √V

Calculation

At 16 kV, resolving power is R. At 4 kV:

(R / R₂) = √(16/4) = √4 = 2

So, R₂ = 2R.