Electrons used in an electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased associated to 100 kV then the de-Broglie wavelength associated with the electrons would

Options

(a) increase by 2 times
(b) decrease by 2 times
(c) decrease by 4 times
(d) increase by 4 times

Correct Answer:

decrease by 2 times

Explanation:

λ ∞ 1/√V
λ₁ / λ₂ = √ V₂ / V₁ = √ 1000keV / 25 keV = 2
λ₂ = λ₁ / 2