If the de Broglie wavelengths associated with a proton and an $\alpha$-particle are equal, then the ratio of velocities of the proton and the $\alpha$-particle will be: (1) $1 : 4$ (2) $1 : 2$ (3) $4 : 1$ (4) $2 : 1$
If the de Broglie wavelengths associated with a proton and an $\alpha$-particle are equal, then the ratio of velocities of the proton and the $\alpha$-particle will be:\\
(1) $1 : 4$\\
(2) $1 : 2$\\
(3) $4 : 1$\\
(4) $2 : 1$