0
You visited us 0 times! Enjoying our articles? Unlock Full Access!
Question

Wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crystals. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere constructively (see figure).
Electrons accelerated by potential V are diffracted from a crystal. If d=1Ao and i=30 , V should be about :
(h=6.6×1034js,m=9.1×1031kg,e=1.6×1019c)
4605_429b816cb4b74f5e9b354e15ffa2062d.png
  1. 2000 V
  2. 50 V
  3. 500 V
  4. 1000 V

A
1000 V
B
2000 V
C
500 V
D
50 V
Solution
Verified by Toppr

We have,
2dsinθ=nλ
angle of incidence = 90i
Given i=30o, d=1×1010m, h=6.6×1034, m=9.1×1031 and e=1.6×1019
Also n=1 for 1st order diffraction.
Therefore,
2×1×1010sin(9030)=1×λ
λ=2×101032=3×1010m
We have de-Broglie wavelength, λ=hmv
and also 12mv2=eV v=2eVm
Substituting in de-Broglie wavength, we get,
λ=h2meV= 3×1010m
V=49.86V

Was this answer helpful?
0
Similar Questions
Q1
Wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crystals. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere constructively (see figure).
Electrons accelerated by potential V are diffracted from a crystal. If d=1Ao and i=30 , V should be about :
(h=6.6×1034js,m=9.1×1031kg,e=1.6×1019c)
4605_429b816cb4b74f5e9b354e15ffa2062d.png
View Solution
Q2
Electrons accelerated by potential V are diffracted from a crystal. If d= 1˚A and i30o, V should be about (h=6.6×1034Js,me=9.1×1031kg,e=1.6×1019C)
213590_bab0bea41851475d8e20d13c094b41bd.png
View Solution
Q3
Electron accelerated by potential V are diffracted from a crystal. If d=1A and i=30. V should be about h=6.6×1024Jsme=9.1×1033kg.e=1.6×1019C
View Solution
Q4
In Davisson-Germer experiment, as shown below, where electrons are reflected from a crystal plane.


If at angle i, the peak diffraction is observed, the de Broglie wavelength of electrons can be calculated by
View Solution
Q5
De-Broglie wavelength of an electron accelerated by a voltage of 50 V is close to: (|e|=1.6×1019C,me=9.1×1031kg,h=6.6×1034Js).
View Solution