CBSE Class 12 · 2005 · All India · Modern PhysicsShort Answer

Mention the significance of the Davisson-Germer experiment. An

α

-particle and a proton are accelerated from rest through the same potential difference

V

. Find the ratio of the de-Broglie wavelengths associated with them.

Answer: Confirms matter waves; $λ_{α} : λ_{p} = 1 : 22$ .

Solution

Significance: the Davisson–Germer experiment experimentally established the wave nature of electrons (the existence of matter waves) by showing electron diffraction from a nickel crystal.
For a charge accelerated through

V

λ = \frac{h}{2 m q V}

, so

\frac{λ _{α}}{λ _{p}} = \frac{m _{p} q _{p}}{m _{α} q _{α}} = \frac{1}{4 \times 2} = \frac{1}{2 2} .

λ_{α} : λ_{p} = 1 : 22

CBSE Class 12 Board · 2005 · All India · Subjective

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