The de-Broglie wavelength of the electrons is given by: λ=h2meV Here: m = mass of the electron = 9.1×10-31 kg e = charge on the electron = 1.6×10-19 C V = accelerating potential = 50 kV h = Planck's constant = 6.626×10-34 Js ⇒λ=6.626×10-3429.1×10-311.6×10-1950×103⇒λ=0.0549 Ao Resolving power of a microscope, R=2μsin θλ This formula suggests that to improve resolution, we have to use shorter wavelength and media with large indices of refraction. For an electron microscope, μ is equal to 1(vacuum). For an electron microscope, the electrons are accelerated through a 60,000 V potential difference. Thus the wavelength of electrons is found to be, λ=12.27V=12.2760000=0.05 Å As, λ is very small (approximately 10-5 times smaller) for electron microscope than an optical microscope which uses yellow light of wavelength (5700 Å to 5900 Å). Hence, the resolving power of an electron microscope is much greater than that of optical microscope.