Question

If a proton and electron have the same de-Broglie wavelength, then

• A. Kinetic energy of electron < kinetic energy of proton
• B. Kinetic energy of electron = kinetic energy of proton
• C. Momentum of electron > momentum of proton
• D. Momentum of electron = momentum of proton
• E. Momentum of electron < momentum of proton

Answer 1

Answer: (D)

Momentum of electron = momentum of proton

de-Broglie wavelength is given by $\lambda =\frac{h}{p}$,

Where $h$ is $Planc{k}^{\prime }s$ constant so $same$ for both electron and proton.

$p$ is $momentum$ of the particle, as both have same wavelength so $momentum$ should be $same$ for both of them.