If alpha, beta and gamma rays carry same momentum, which has the...

On the basis of dual nature of light, Lious de-Broglie suggested that the dual nature is not only of light, but each moving material particle has the dual nature. He assumed a wave to be associated with each moving material particle which is called the matter wave. The wavelength of this wave is determined by the momentum of the particle. If $p$ is the momentum of the particle, the wavelength of the wave associated with it is $\lambda=\frac{h}{p}$ where $h$ is Planck's constant. Since, it is given that, alpha, beta and gamma rays carry same momentum, so they will have same wavelength.