The de Broglie wavelength of an electron accelerated to a potential of $ 400 \,V $ is approximately (in $\,nm$)

If an electron and a photon propagate in the form of waves having the same wavelength,it implies that they have the same

What are called matter waves? Name the devices which employ the use of these matter waves.

If the kinetic energy of a free electron doubles,its de-Broglie wavelength changes by the factor

$A$ particle is travelling $4$ times as fast as an electron. Assuming the ratio of the de-Broglie wavelength of the particle to that of the electron is $2:1$,the mass of the particle is:

The ratio of the de-Broglie wavelengths for the electron and proton moving with the same velocity is ($m_p$ = mass of proton,$m_e$ = mass of electron).