Given below are two statements: one is labelled as **Assertion A** and the other is labelled as **Reason R**.
**Assertion A:** An electron microscope can achieve better resolving power than an optical microscope.
**Reason R:** The de Broglie's wavelength of the electrons emitted from an electron gun is much less than wavelength of visible light.
In the light of the above statements, choose the correct answer from the options given below:
Answer: (B) Both A and R are true and R is the correct explanation of A
The smallest separation a microscope can resolve is proportional to the wavelength used.
Accelerated electrons have de Broglie wavelengths far smaller than visible light (e.g. about $0.01$ nm at tens of kV versus $400$–$700$ nm), so an electron microscope resolves much finer detail.
Both statements are true, and R explains A.
Solution by Sreeraj P, M.Sc Physics