Machine-translated by Google. Questions are authored in English.
Top

Discussion

The wavelength associated with a particle in one-dimensional box of length L is (n refers to the quantum number)

  • A.2L/n
  • B.L/n
  • C.nL
  • D.L/2n

Answer: A

The wavelength is 2L/n.

The wavefunctions of a particle in a box, \(\psi_{n} = \sqrt{2/L}\,\sin(n\pi x/L)\), must vanish at both walls, so they are standing waves with a whole number of half-wavelengths fitting into the box:

\[ L = n\frac{\lambda}{2} \Rightarrow \lambda = \frac{2L}{n} \]

For the ground state (n = 1) the box holds half a wavelength, so \(\lambda = 2L\). L/n counts whole wavelengths instead of half-wavelengths, L/2n halves the answer again, and nL would make the wavelength grow with the quantum number, when higher states have more nodes and shorter wavelengths.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.