Which one of the following statements is not true of de-Broglie waves
(a) All atomic particles in motion have waves of a definite wavelength associated with them
(b) The higher the momentum, the larger is the wavelength
(c) The fater the particle, the shorter is the wavelength
(d) For the same velocity, a heavier particle has a shorter wavelength
Option (b) The higher the momentum, the larger is the wavelength
Explanation :
As,λ = h/p = h/mv
where, h = Planck’s constant, λ = wavelength, p = mv = momentum
It is shown that wavelength λ is inversely proportional to the momentum. Hence, lighter the momentum, lesser will be the wavelength. So, statement (b) is not true.
Option (b) is incorrect ,
Explanation
By deBroglie equation we know ,
λ = h/p = h/mv
where, h = Planck’s constant, λ = wavelength,
p = mv = momentum
As the wave length λ is inversely proportional to momentum mv . So higher the momentum shorter is the wavelength.