As we know, de Broglie wavelength is given by,
λ=ph
Now kinetic energy can be written as,
K=21mv2=2mp2=2mλ2h2
Therefore,
K∝m1
Hence, required ratio
KαKp=mpmα=4⇒mα:mp=4:1
JEE Main 2023 — Physics Modern Physics
A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of λ. An alpha particle having certain kinetic energy has the same de-Brogle wavelength λ. The ratio of kinetic energy of proton and that of alpha particle is :
Held on 1 Feb 2023 · Verified 6 Jul 2026.
2:1
4:1
1:2
1:4
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