Question

In Davisson and Germar experiment, the intensity of the scattered beam of electrons is maximum for diffraction angle ${50}^{\circ }$ at 54$V$ potential difference with nickel crystal Then de-Broglie wavelength of electron is (approximately)

• A. $1.6A^0$
• B. $5A^0$
• C. $6A^0$
• D. $8A^0$

Answer 1

The correct option is A $1.6A^0$

In Davisson and Germar experiment, the intensity of the scattered beam of electrons is maximum for diffraction angle ${50}^0$ at $54V$ potential difference with nickel crystal.

The angles of maximum reflection are given by Bragg's condition for constructive interference from an array, Bragg's law i.e.,

$n\lambda =2dsin({90}^0-\frac{\theta }{2})$

for $n=1,\theta =50°$, and for the spacing of the crystalline planes of nickel $(d=0.091nm)$

$\lambda =2\times 0.091\times {10}^{-9}sin({90}^0-\frac{{50}^0}{2})=1.6A^o$