The de-Broglie wavelength of a proton and α - particle is same. The ratio of their velocities will be……….
(α particle is the He-nucleus, having two protons and two neutrons. Thus, its mass Mα = 4mp where mp is the mass of the proton.)
(A) 1:4
(B) 1:2
(C) 2:1
(D) 4:1
