If the de - Broglie wavelengths for a proton and for an `alpha` - particle is equal , then what is the ratio of velocities for proton and alpha particle?

If the de Broglie wavelengths associated with a proton and alpha particle are equal then the ration of velocites of the proton and the alpha paricle will be :

The ratio of the de Broglie wavelength of a proton and alpha particles will be 1:2 if their

The ratio of the e/m values of a proton and an alpha -particle is:

Find the ratio of de Broglie wavelength of proton and alpha -perticle of same energy

The de-Broglie wavelength of a proton and an electron are equal. The it follows that