Electron beam used in an electron microscope, when accelerated by a voltage of 20 kV, has a de- Broglie wavelength of λ₀. IF the voltage is increased to 40 kV, then the de-Broglie wavelength associated with the electron beam would be: (a) 3 λ₀ (b) 9 λ₀ (c) (λ₀)/(√(2)) (d) (λ₀)/(2)

Answer: (c). λ ∝ 1/√(V). (λ')/(λ₀) = √(20/40) = 1/√(2). So the answer is (c) (λ₀)/(√(2)).

Electron beam used in an electron microscope, when accelerated by a… | JEE Main 2023 (25 Jan, Shift 1)

Q67JEE Main 2023 · 25 JAN · SHIFT 1Easy

Matter Waves: de Broglie Wavelength

Electron beam used in an electron microscope, when accelerated by a voltage of 20 kV, has a de- Broglie wavelength of $\lambda_0$ . IF the voltage is increased to 40 kV, then the de-Broglie wavelength associated with the electron beam would be:

Show answer and solution

Answer: (c)

$\lambda \propto \dfrac{1}{\sqrt{V}}$ .
$\dfrac{\lambda'}{\lambda_0} = \sqrt{\dfrac{20}{40}} = \dfrac{1}{\sqrt{2}}$ .
So the answer is (c) $\dfrac{\lambda_0}{\sqrt{2}}$ .

Report a mistake

Matter Waves: de Broglie Wavelength question from JEE Main 2023 (25 Jan, Shift 1)

More questions on Matter Waves: de Broglie Wavelength