Target Exam

CUET

Subject

Physics

Chapter

Dual Nature of Radiation and Matter

Question:

If the mass of neutron = $1.7×10^{-27}kg$, then the de Broglie wavelength of neutron of energy 3 eV is (Take $h =6.6×10^{-34}Js$)

Options:

$1.6×10^{-10}m$

$1.6×10^{-11}m$

$1.4×10^{-10}m$

$1.4×10^{-11}m$

Correct Answer:

$1.6×10^{-11}m$

Explanation:

Here, $E= 3eV=3×1.6×10^{-19}J$

de Broglie wavelength, $λ=\frac{h}{\sqrt{2mE}}$

$=\frac{6.6×10^{-34}}{\sqrt{2×1.7×10^{-27}×3×1.6×10^{-19}}}=1.6×10^{-11}m$