Question

An electron and a proton have the same De Broglie wavelength. Then the kinetic energy of the electron is :

• A. Zero
• B. Infinity
• C. Equal kinetic energy of proton
• D. Greater than the kinetic energy of proton

Answer 1

The correct option is C Equal kinetic energy of proton

We know that,

$E=hv=\frac{h_c}{\lambda }$ is the fundamental relation.

$E=cp$

$\Rightarrow cp=\frac{h_c}{\lambda }$ or $\lambda =\frac{h}{p}$

Thus, it is evident that same de-Broglie wavelength implies, Total energies of the particles are equal.